Which should I join? Which microstock photography site should I use to sell my photos online?

Shutterstock
You will earn the most money at shutterstock, guaranteed!

Fotolia
Good site. Good sales. Highly recommended!

Dreamstime
Regular sales, very stable, quite fussy about your images.

Istock Photo
Very fussy, small upload limit, good sales!

Bigstock Photo
Slow on sales, but high acceptance ratio. Easy to use and therefore recommended.