I've been writing my own service, Score Lab, for sports schedules, scoring, and standings for nearly a year now. Just recently, I had the opportunity to use try it out on a real competition, the Click Rain Bake-Off, and the process has been incredible for usability.
I wrote much of Score Lab anticipating the needs of my future clients, and trying everything out with test data. However, actually using the site with real data has provided countless insights. With real data, and real use, little improvements and little bits of polish here and there become so much more obvious. Sharing to social media has surfaced improvements in metadata. Any little frustration I come across gets fixed, almost immediately. Even the fear of showing off a previously unseen app to a new audience allowed me to see Score Lab in a new light.
So much of the software I've written in my career has been intended for use by other people. But over and over again, the software I write for myself has that special bit of polish that only comes from personal use. Dogfooding is not a new idea, but every time I get the chance, I'm reminded of how useful it can be.