There is a payslip floating around where a grammy award artist gets around 30 bucks from his online streaming royalties all combined. In the business model, it is not a source of revenue anymore, I think it is better to consider it a permanent ad campaign than an income.
EDIT oh and iTunes on mac is neat, I don't see the need of anything else. It does not lag and serves a lot of purposes, the main one being a hassle free big play button. Any mp3 i have is put on the icon and therefore included, sorted, with the cover and all, in a few seconds, and I can delete it. I simply keep a specific folder for random mp3 which don't really belong in a music library, and I use VLC usually for these. I love VLC but life is too short to loose time hand managing a library anymore
On windows I loved Mediamonkey. Clean simple and efficient