Haven't got time to do the maths but I do know that IS is getting very frustrating for me; falling downloads, annoying upload limits and procedure.

Fotolia continues to be my highest earning site, followed by IS (despite it's flaws), then SS and DT. DT sales have slowed quite a bit for me but hoping revenues pick up with the new prices.

Feb was a pretty good month for BigStock and StockXpert. 123rf still languishing behind these but in front of CS.

fotolia your highest?  wow, didn't know they were doing that well for some people.  not bad!