Not everyone featured in this Crain's Chicago Business article expected to launch the next Stuff White People Like or Julie/Julia Project. But all of them expected to get at least something out of the time they put into their blogs that never materialized.
It's too easy for people to think, "hey, it's just a blog, it won't be that hard and I'm special and the internet will find me and then I'll be famous like that guy with the funny cat pictures." What they (you?) need to realize is that internet audiences are fickle, stingy, and demanding, and you put your time and self-worth in their hands at your peril. The most successful blogs are ones that cover something (e.g. a project, a pop cultural phenomenon, a point of view) that would exist whether or not the blog does. Blogs are good for documenting culture, not manufacturing it.