[fredley]

It depends if it's a project that is going to grow. For so many things Bootstrap does so much for so little effort. I use it any time I need to spin something up quickly, prototype an idea, put an internal page together. Bootstrap is a tool for making a page where you don't care how it looks look good.

[WorldMaker]

It also depends on how the project is going to grow. If I'm the only lead dev on a team that's only going to see a revolving door of junior devs and interns, it's much easier for me to point to Bootstrap's documentation page and say "just copy the example from here" than it would be to get junior devs quickly up to speed on any custom CSS framework. There's even a chance a junior dev is already going to be familiar with Bootstrap from a previous project.