Of those listed Alamy is the biggest and is based in Europe.
The rest are microstock agencies.
Most of those stock houses have their royalty schedule online, if you get motivated enough to go look at them.
The profit is split heavily in favor of the stock house, and is usually a sliding scale based on how many of your images sell.
If just a handfull of your photographs sell you get paid the minimum split.
If boatloads of your photos sell you get paid a better split, but it still doesn't add up to anywhere close to what photographers once made from stock photography.
There are several variables that determine how much a stock house charges for one of your images, like exclusive use or non-exclusive use and the type of use license
Understanding stock image licensing
With most stock agencies today you won't get paid until you reach a minimum amount, - $50, $75, or $100.
Based on 123RF's commission schedule you'll earn 21.6
cents for every 2.075 100 Mb TIFF images they sell.
So if 123RF pays when you have $50 or more due, to get to $50 123RF would need to sell 232 of your images.
The problem is most RF (Royalty-Free) use
licenses grant the buyer up to 500,000 uses of your image.
So basically, 123R wants to sell 3 of your 100Mb TIFF photos before you make 25
cents.