Joel, writes up an interesting example of NOT eating your own dog food, (ie using the IT solutions you are developing yourself), until it was almost too late:
Eating your own dog food is the quaint name that we in the computer industry give to the process of actually using your own product. I had forgotten how well it worked, until a month ago, I took home a build of CityDesk (thinking it was about 3 weeks from shipping) and tried to build a site with it.
Phew! There were a few bugs that literally made it impossible for me to proceed, so I had to fix those before I could even continue. All the testing we did, meticulously pulling down every menu and seeing if it worked right, didn’t uncover the showstoppers that made it impossible to do what the product was intended to allow. Trying to use the product, as a customer would, found these showstoppers in a minute.
And not just those. As I worked, not even exercising the features, just quietly trying to build a simple site, I found 45 bugs on one Sunday afternoon. And I am a lazy man, I couldn’t have spent more …