When you start selling your images on microstock sites, at some point you may ask yourself if you should become an exclusive contributor or not? The answer depends on several things. If photography is just a hobby for you, you only wish to have a little side income, and your time is very limited, then exclusivity can be a good option. And iStock would definitely be the best site. But I believe that if you submit your work to all the best microstock agencies, you will earn much more than if you go exclusive with only agency.
Exclusive contributors get much higher commissions. Other benefits may include faster review times and lower upload limits. Some microstock sites offer a possibility to upload exclusive photos without becoming an exclusive contributor. That might be worth trying, but I still believe that the best thing is to submit to multiple sites.
Creating an image takes much longer than uploading it to a stock photo site. If you have done all this work – you took a photo, you edited it, you wrote keywords, title and description, – then 95% of the work is done. If you use FTP batch uploading and the keywords are already embedded into the image, uploading to 10 sites won’t take that much longer than uploading to just 1 site. But the payout will be substantially higher.