I signed up with DT a few years ago, but didn't start uploading until may last year.
I only had 3 months of experience with studio and flash photography (I was a macro/insects shooter for 2 years prior to that), so I really didn't expect to sell anything (here or elsewhere).
The first few months, sales on DT were (indeed) dramatic, but I soon discovered that insects are no big sellers when it comes to microstock. So, I checked various microstock sites, in order to find out which subjects did well and if there was something, anything that I would be interested in shooting (as after all... I wanted to enjoy the photographing and not 'just make money')
So, I found myself doing all different kinds of things and the learning process/curve has been huge. I currently have an acceptance ratio of 94.4% here (I was at 95.9% last month, but a few 'similarity rejections' killed it) and I think this shows in sales. There's a BME almost every month and today I reached $500 in sales here on DT!
I'm working with the "big 4" (i.e. the 4 biggest agencies) and DT not only shows the best progress, sales wise, but it's also the best paying agency! And the difference in dl/revuenue compaired to other agencies is HUGE! I admit that the similarity rejections still confuse (and at times annoy) me, but overall I am very pleased with DT. Not just when it comes to sales, but in general. Customer support is always fast and very friendly/helpful. Questions asked on the forum are in most cases extensively answered by admins and my overall impression with DT is that they are not just a business (thinking as a business) but that they really care about their contributors and that they try to be fair and transparent in any regard.
So, thank you DT for the wonderful experience and for giving me the chance to sell my work through your site! :-)