Adobe's Ideas has an 8 minute "user guide" (http://www.youtube.com/watch?v=nILS13_b2p8&feature=playe...). 37Signals's Draft presumably doesn't require a user guide.

If all you want to do is what Draft offers, then the extra "features" of Ideas just get in the way. It's worthwhile for some people to pay $10 for a tool that works very well rather than make do with a free, but less-than-ideal alternative.

The two products are a great example of how one can profit by selling a product with fewer features.

The key is to understand the product from the user's point of view. Draft was meant to replace a sharpie and a paper notebook. Ideas is MS Paint for the iPhone. Although the two apps have an overlapping feature set, they don't present the same value to the user.