It’s understandable. Potential customers want to know if they can trust what’s put in front of them. How reliable is this data?
We think it’s the most accurate, best-in-class SEM data available without drilling right into your Adwords account.
First, every piece of information you see on SpyFu — every ad, every organic rank — can be traced back to a specific Search Engine Result Page *(SERP)* that we saw on Google. We keep a screenshot of every single one going back over 9 years to when we first started collecting data.
When we say that some domain was advertising on a certain keyword at 3PM on July 12th 2015, we have indisputable visual proof that they were. Same goes for organic rankings. This is iron-clad 100% fact.
From that foundation, we can carefully calculate other roll-up metrics like Clicks per Day and Estimated Budget. When we say “carefully calculate” we mean that we’ve grown obsessed with reverse engineering Adwords and Google Analytics accounts for every domain we come across, building sophisticated algorithms to take into account what happens before anyone clicks a link on a SERP. To our nerdy brains this is the most exciting thing in the world.

Where We Get These Stats
In their keyword tools, Google tells us how many searches each keyword gets per month, and how much each one costs to buy in Adwords. From here, it gets fun.
There are a lot of variables that go into each part of the problem — take the organic click through curve, for example: the number one search result normally converts about 21% of searches into clicks. But, when there are shopping results on the page, it drops to about 8%. And what about Ads, and videos, news, images… we take all those things into account — for every single keyword — for every single domain.

About 5 years ago, SEOOptimise.com did an independent study against their client data that found that our Budget estimates were accurate 79% of the time.
We’re very passionate about solving the problem, and that keeps us looking for ways to improve. Since that SEOOptimise post, we’ve made many improvements including the example about taking shopping, video and other results into account. Realistically, these days, you can expect our roll-up estimates like Ad Budget and SEO clicks to be accurate about 90% of the time.
That said, we have a good grasp of scale. If we say a domain is spending $10,000. There’s no way they’re spending $500 or $100,000.
And When We Get it Wrong…
Here’s even better news: When we’re wrong, we’re consistently wrong in an industry. So, if you’re trying to size up your competitors all you have to do is calibrate their numbers against your numbers. Make sense?
Let’s say that your domain is MeatYums.com and we think your Adwords budget is $10,000/mo. But, you know that you’re really spending $20,000/mo. When you look at your competitor MeatyProducts.com and we say that they are spending $18,000/mo, then you should calibrate our estimate based on your inside knowledge to $36,000.
Being off consistently within an industry comes directly from the noisy CPC and search volume data we get from Google. You’ve probably seen it yourself using the Google Keyword tools. We’re working with the same data. When we’re inaccurate it’s because that input data is inaccurate , and it affects all advertisers or organic rankings across the board.
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UPDATE: Thanks to some feedback, I’ve added a screen shot of exactly where you can get to the cached SERP page screen shots for any keyword.
