Evan Williams is co-founder of Blogger, Twitter (on which he's known as @ev), and, most recently, the blogging platform Medium. He told his story to Inc. reporter Issie Lapowsky.

When I meet with the founders of a new company, my advice is almost always, "Do fewer things." It's true of partnerships, marketing opportunities, anything that's taking up your time. The vast majority of things are distractions, and very few really matter to your success.

Anything I've done that really worked happened because, either by sheer will or a lack of options, I was incredibly focused on one problem. Blogger started as a side project of my first company, Pyra Labs. Initially, we were trying to do both, but it became impossible. We ran out of money, had to let everybody go, and I just did whatever was necessary to keep Blogger running. If I had been more aware back then of the importance of focus, I would have killed the original project way sooner.

With my next company, Odeo, we thought we were going to be the podcasting company. We would do it all: make software to create podcasts, a directory for discovering them, software to download them. But none of these solutions were great. We should have started with a specific product that did one thing better than anyone else. Instead, when iTunes introduced its podcasting platform, it obliterated the value we had created.

With Twitter, which was a side project of Odeo, it wasn't clear at first what it was. Initially, we described Twitter as a social utility for posting status updates, but the insight we eventually came to was Twitter was really more of an information network than a social network. That influenced all kinds of decisions, like the creation of search and the retweet function. And all of that happened because we were thinking deeply about a very specific product.

When you're obsessing about one thing, you can reach insights about how to solve hard problems. If you have too many things to think about, you'll get to the superficial solution, not the brilliant one.

The irony, of course, is that both Blogger and Twitter started as side projects. If I had been absolutely focused on the main project, they might never have happened. So, there is something to be said for knowing when you're locked in to the right problem.

To me, that comes down to the gut. The things that keep nagging at you are the ones worth exploring.