I was talking to an analyst about how SEO works, and we inevitably got to the authority side of SEO. I started talking to him about how many companies spend a lot of effort trying to get external links to their site to build authority. It’s not something we have to worry about at Pinterest as our authority is super high naturally, but most companies do not have that luxury. The analyst, being a good analyst, asked how you track effectiveness of link building as a program. My answer surprised him: most of the time, you don’t.

Sure, sometimes you can see a correlation between link building and average weighted rank improvement, and maybe you didn’t make any improvements on the relevance side during that time. But, while you can experiment with SEO in relevance changes, it is pretty much impossible to experiment with link building as it works at both a domain and page level, its impact is felt over such a long period of time, and there are almost always so many other factors one can’t control, namely from competitors for those same search results.

So, he then asked, how do we know it works? The answer is: we usually don’t. So, the next question of course is, if it’s a pain to do and we don’t know it works, why do we do it? This question can be generalized to almost any competitive question via game theory. To really hammer the point home though, I actually used the climate change example.

In climate change, their are four scenarios and two dimensions. The first dimension is whether or not it is actually happening (or whether it’s man made), and the second dimension is whether we do something about it.

Next, you examine the outcome of each scenario to determine the outcome if that’s the box you pick.

As you can see here, in every box you are fine, except for the upper left. Sure, you might have wasted quite a bit of money and slowed the growth of some businesses, but none of that compares to possible catastrophe. Even if you think it’s a waste of time, the risk is so great if you’re wrong, and the answer reveals itself over such a long period of time, the obvious answer becomes to assume it is true and invest in fixing it.

Now, let’s apply this to a much less risky scenario of link building.

While we aren’t saving the world when we work on SEO, from a business perspective, the risk is just as great. In one belief, you lose, and in all other scenarios you don’t. If your competitors are smart, they all do this exact analysis and come to the same conclusion: to invest in link building. This cannot be a prisoner’s dilemma either, as one company always outranks another, and links occur organically that presumably change the rankings.