I had a few issues regarding multiple Facebook pages and access in which I had to log-out and in to access my account. Support was very good, but I wish they could figure out how to access all accounts with one password or Facebook account.
ROI was great. People remembered our company and products after the contests. This of course has to do with how much money you spent promoting, but I think Woobox made it a simpler process for people to enter a contest.
Support was quick and efficient. Product has a lot to offer outside of Facebook contests that I would like to try in the future. I cannot stress enough how easy this product was to use. Up and running in five minutes.