To use the service you buy however many credits you want and then you use them pay for whatever you download. Photos are 1 to 6 credits depending on the size you want. Illustrations (vectors thank you!) are mostly 5 credits. Video is 5 to 20 credits. Flash animations seem to vary a bit, but the ones I've seen are usually 1 credit.
The site itself is very Web 2.0 and to delve into all the cool features would take an awfully long post, but the short list would include:
- User ratings
- A great Lightbox utility
- A creative network
- A blogging tool
Not only do I get a lot of use out of the site, but I have often started simply surfing around to check out all the cool stuff available. I can't say I've done that with many other commerce sites.