I enjoy using this service because it's easy for me as an artist who doesn't have time or knowledge about computers to use their services without having to worry too much.
It can be difficult at times if you aren't used to working online but they do offer tutorials that are helpful when needed. They also send out emails reminding users how long certain products will stay up so there isn't anything negative I would like to mention other then maybe trying some new things here and there could help improve your experience overall! I love being able to upload my own artwork into stock images instead of paying others to create them. As well, once uploaded I am notified by email whenever someone purchases one of these items which makes selling faster since no waiting around until orders come throught he site only to find nobody has bought something yet.