Business owners, regardless of their industry, often view themselves in terms of what their business does. “We’re a bookstore, a coffee shop, a web design company,” or whatever goods or services that customers pay money for. But a recent conversation made me realize that most small businesses in a mature market are really a search engine optimization (SEO) company.

Okay, there are a few caveats here. I’m thinking of mature markets as fields where there are many small or small-ish players that are attempting to serve a large number of users. Think generally of the early and late majority sections of the technology adoption life cycle. Ride sharing, for example, is out of scope. It’s pretty solidly in the middle of the bell curve, but it has three players: Uber, Lyft, and everyone else.

The subject of the conversation was a VPN service. A friend was using VPN software and observed that it would be easy to share his server with others for a fee. All the other challenges of running a business aside, I immediately asked what his differentiation is.

VPN services may not be mainstream exactly, but the market is mainstream enough. And there are a lot of players with no one particularly dominant. So how does a new entry set itself apart? There’s a little bit of room to differentiate on price, location, service, etc, but not much. So the best way to differentiate and get new customers is to be better at search engine optimization than the rest of the field.

In essence, making a business successful requires skills entirely unrelated to the business itself. When you can’t easily differentiate your product, you have to differentiate your marketing.