I don't think I fit into the "years" catagory, but I think I know what you're asking.
I've been doing this long enough to be too embarrased to admit that it took me about a year of playin with little projects here and there to finally get 1 sale.
Once I started paying for my own domains/hosting, and actually playing with the other kids, took me about... 3 months to start getting the rest.
edit: oh... and I wouldn't be surprised if that first sale was a friend giving me a nice push.
