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How to calculate SEO ROI

Cancelled events, telesales teams calling empty offices and a lack of face-to-face networking opportunities has led many B2B organisations to consider SEO for the first time (don’t believe me? Take a look at this Google Trends graph from the last 12 months). But before taking the leap they need to establish what SEO return on investment (ROI) might look like.

Return on investment is typically measured as a percentage or a ratio so it can easily be compared to other marketing investments. Search engine optimisation ROI can be measured by working out the gain from the SEO investment, subtracting the cost of the investment from that gain, and then dividing that number by the cost of the investment and multiplying it by one hundred. For example:

Gain from SEO = £275,000

SEO investment = £100,000

Difference = £175,000

£175,000 / £100,000 = 1.75

1.75 x 100 = 175% SEO ROI

Put simply, this means that every £1 invested in SEO paid for itself and then generated an additional £1.75 in gain.

Types of SEO investment

In order to work out the ROI you need to know what your gain from SEO is and what your investment is. Sounds obvious right?

For a straightforward ecommerce business selling shoes for example, it’s  pretty easy to work out ROI – because the gain is as simple as the value of goods (shoes) sold from customers sourced through SEO activity. You can add ecommerce tracking to your website, assign revenue values to goal completions and away you go – very easy to work out your gains in Google Analytics.

Lead generation B2B sites are a bit different. This is because a website isn’t where a B2B sale is typically completed i.e. for many B2B businesses, sales are initiated when the prospect contacts the company (via form or phone), but sales cycles are often much longer and have multiple touch points.

You therefore need to assign values to different types of conversions – it’s not as straightforward as saying a customer spent £30 on product A therefore our gain is… instead it’s a case of saying a customer submitted an enquiry form to enquire about a particular service and if they convert, they’re worth X amount over the course of their lifetime.

But it’s not just about form submissions, you can also assign values to other types of conversions that are really important to the B2B sales cycle.

For example if you generate loads of eBook downloads using SEO and you know that typically every ten eBook downloads will result in one paying customer, then that helps you work out your ROI.

For example if the total value of customer (gain) generated from ten eBook downloads = £30,000

And the investment total…

  • SEO agency consultancy (investment) that led to ten eBook downloads = £5,000
  • Cost of creating blog and eBook content (investment) = £5,000
  • Cost of nurturing leads until conversion over six month period (investment) = £10,000

…is £20,000

Then the difference is £10,000

£10,000 / £20,000 = 0.5

0.5 x 100 = 50% SEO ROI

Put simply, this means that every £1 invested in SEO paid for itself and then generated an additional 50p in gain.

The above example is important. Search engine optimisation will typically involve lots of different types of investment from both the agency you hire to support you, as well as your internal resource, whether that be marketing and/or sales.

However it’s rare you’d employ an SEO agency to focus on a series of eBooks like in the example above. It’s more likely they’d consider your micro conversions (like eBook downloads, webinar registrations and/or newsletter signups) along with macro conversions like consultation form enquiries.

It’s therefore really important to know how much your micro conversions are actually worth. However, it is VERY rare to find B2B organisations that know this. (It’s also rare to find B2B organisations that know what their organic conversion rates are for micro and macro conversions – we’ll come on to that later.)

If you do know your conversion values then you can start customising Google Analytics to report on goal value i.e. if every ten eBook downloads generate £30,000 worth of revenue then in theory every eBook download is worth £3,000.

The goal that completes in Google Analytics whenever someone on your site downloads an eBook can then be assigned a £3,000 value and it becomes easy to review your SEO ROI for that particular conversion.

So let’s take another look at a more realistic B2B SEO ROI calculation over a 12-month period:


Total value of customers from eBook downloads generated from SEO = £30,000

Total value of customers from newsletter signups generated from SEO = £25,000

Total value of customers from webinar registrations generated from SEO = £45,000

Total value of customers from consultation form completions generated from SEO = £250,000

Total gain: £350,000


SEO agency investment = £115,000 (incidentally, read this if you’re interested in how much SEO costs)

Cost of creating blog, eBook, newsletter, webinar and optimised website content = £35,000

Cost of nurturing leads, until they convert, over six month period = £27,000

Total investment: £177,000


£350,000 – £177,000 = £173,000

SEO ROI calculation

£173,000 / £177,000 = 0.98

0.98 x 100 = 98% SEO ROI

Put simply, this means that every £1 invested in SEO paid for itself and then generated an additional 98p in gain.

Attribution models

So far we’ve considered SEO’s role as a last click driver of leads i.e. the last thing a prospect does before they become a lead that either needs to be nurtured or converted is click on an organic search result. But what about SEO’s role in other types of conversion? This is where a B2B organisation needs to consider attribution modelling.

Attribution modelling is basically the decision to assign a marketing channel a particular value. For example, in a linear attribution model every touchpoint in the conversion path shares equal credit for a sale. So if a qualified lead clicked on a paid Google ad, downloaded an ebook that they found via organic search, visited your website directly and then eventually visited via LinkedIn, before submitting an enquiry form during that session, each of the four channels would be awarded a quarter of the credit.

The attribution model therefore impacts your gain calculation, which then impacts your SEO ROI calculation.

Attribution models include:

  • Last Non-Direct Click
  • Last Google Ads Click
  • First Interaction
  • Linear
  • Time Decay
  • Position Based

For more detail on attribution modelling have a read of Google’s overview of attribution modelling.

How to increase your SEO ROI

Fundamentally your SEO ROI will be dependent on your keyword rankings. The higher you rank for the right keywords, the more traffic you generate, the more leads you’ll generate. And the ranking gains are significant. Let’s consider a macro conversion example – a prospect landing on your website and submitting a consultation form.

First off, let’s take a single bottom of sales funnel keyword – one that you want your website to rank for because you think it’ll lead to prospects contacting you that you can do business with. Let’s say the keyword is ‘B2B SEO agency’. We want to rank for that because we know someone searching for B2B SEO plus the modifier ‘agency’ is probably looking for an agency and therefore someone we want to talk to.

Let’s say the keyword gets 200 searches a month.

We know that the unbranded click through rate (CTR) for the first placed organic search result is 31% and fifth place CTR is 7% (according to CTR data from Advanced Web Ranking).

Let’s also say we know that ten percent of the organic visitors to our site will submit an enquiry form.

Let’s say half of those enquiries are qualified and we close half of the qualified leads.

Therefore if we’re ranking fifth for the keyword then we can expect:

200 x 0.07 (7% – the fifth placed organic CTR) = 14

14 x 0.1 (10% – our onsite organic conversion rate) = 1.4

1.4 x 12 (months in a year) = 17 (16.8 but let’s round up)

So if we rank fifth we know we’ll probably generate 17 leads a year. Half of those are qualified (let’s say eight) and we close half of those (let’s say four). If we know our average customer lifetime value is £40,000, then ranking fifth for that keyword would generate £160,000 a year in revenue.

If we’ve invested £30,000 of our staff’s time in SEO (we have an hourly rate so we can work this out) then we come back to our profitably calculation:

Gain = £160,000

Investment = £30,000

Difference = £130,000

130,000 (difference) / 30,000 (investment) = 4.33

4.33 x 100 = 433% SEO ROI

Put simply, this means that every £1 invested in SEO paid for itself and then generated an additional £4.33 in gain.

Now let’s adjust the ranking CTR. Let’s say we rank first instead of fifth and enjoy a 31% CTR. Everything else (onsite conversion rate, qualified lead and close rate) remains the same:

200 x 0.31 = 62

62 x 0.1 = 6.2

6.2 x 12 = 74

So if we rank first we know we’ll probably generate 74 leads a year. Half of those are qualified (let’s say 37) and we close half of those (let’s say 19). If we know our average customer life time value is £40,000 then ranking first for that keyword would generate £760,000 in revenue.

If we’ve invested £60,000 of our staff’s time in SEO (we have an hourly rate so we can work this out) then we come back to our profitably calculation:

Gain = £760,000

Investment = £60,000

Difference = £700,000

700,000 (difference) / 60,000 (investment) = 11.67

11.67 x 100 = 1,167% SEO ROI

Put simply, this means that every £1 invested in SEO paid for itself and then generated an additional £11.67 in gain.

A pretty impressive return!

SEO ROI considerations

A few final things to consider when working out your ROI:

Different conversion rates for different conversion types

We’ve used an onsite organic conversion rate of ten percent (the percentage of your organic website visitors that convert i.e. submit an enquiry form) in our calculations. However yours might be lower or indeed higher. Your conversion rate is also going to be different depending on the type of conversion you’re measuring. For example you might find a lower percentage of organic visitors download your ebooks. Conversion rate is driven in large part by intent. If someone’s searched for a keyword related to one of your services then it’s likely they have an immediate need and will submit an enquiry. However if they entered the site after searching in Google for the answer to a question, then the conversion rate will likely depend on whether or not you answer their question without them having to download anything.

Conversion rate optimisation

It’s possible to improve the ROI of SEO (and any other online marketing disciple) by improving your onsite conversion rate. This is called conversion rate optimisation (CRO). If you want to learn more about that then read this book: Making Websites Win. If ten percent of your organic visitors submit consultation forms, then think about the knock-on impact if you managed to move that number by a couple of percent. In our original example we considered the impact of ranking first for a keyword with 200 searches at a conversion rate of ten percent. Let’s shift that rate by two percent:

200 x 0.31 = 62

62 x 0.12 = 7.4

7.4 x 12 = 89

So by improving the conversion rate from 10 to 12 percent we can increase leads generated by 15. If half of those are qualified and we convert half of the qualified leads then that’s an additional four deals per year. If each deal is worth £40,000 then that’s an additional £160,000 a year in revenue for a conversion rate improvement of two percent. Certainly worth an investment in CRO.

Paid vs organic

The disparity between what brands invest in paid search and organic search is jaw-dropping. Think about your investment. If you’re pumping hundreds of thousands into PPC then consider what impact diverting some of that funding into SEO will have. Yes pay per click offers greater certainty, but there is ultimately substantially more value in investments in organic search. It is important however, to consider how long SEO takes – unlike PPC it doesn’t deliver immediate results and your ROI will improve the longer you continue to invest, as that investment will result in keyword ranking, organic traffic, lead and qualified lead increases.

Remember, unlike B2C SEO, B2B SEO is often about value not volume: high value low volume sales. Therefore working out your SEO ROI is important for every B2B organisation. If you’re stuck working out your search engine optimisation return on investment, then give us a call – we’re always happy to chat!