As far as microstock photography is concerned, no doubt fotolia is among the big ones. What surprised me is that it's even better (in terms of sales) than those - at least for me.

I don't know why but I would advice it's because it is localised in many countries and it really sells worldwide. And most of my photo sales with Fotolia are in Europe - UK, Germany and France mainly - but Italy and Spain are going pretty well lately. Of course I also have sales in the US but the point here is that - in my opinion - Fotolia sells best than other microstock agencies in Europe.

Here's a list of localised fotolia sites. Should you decide and sell pictures, please choose your link based on your preferred language and payment currency as well. You will be paid with PayPal.