I enter the contests when there is one that fits my shooting style and available models/props. I'm not that concerned at this point with having to leave it for a year. I don't expect to be leaving DT
Can't say it has had a direct impact on my income via huge sales of the contest images, but it does up your exposure IMHO. I get the impression buyers keep an eye on the contests, and if you upload something they like they may take the time to check your other work.
I think that is the best course to take. The images which get accepted appear on the front page, at least until newer accepted images drive it off. So I agree you do get a lot more exposure.
When I got the editor's choice image in early March, not only did the image itself sell multiple times the first week, but my overall sales spiked. If you can get extra exposure at Dreamstime, it's definitely a good thing because volume is respectable, and commissions are very fair.
