This is a great idea that I would use all the time, but I don't understand this trend of posting long blog posts of company ideas. If it's a good idea, why don't you just start working on it?
Perhaps because ideas are a dime-a-dozen, but not every idea-haver has the time, energy, desire, or capital necessary for execution. Perhaps someone else will come along and run with this idea. I think sharing startup ideas aloud in blog posts is wonderful for this reason.