A couple of months ago I got invited to join this site by Delta to help me earn a few extra miles here and there. To date I have ashed-out on 2,500 miles(sure that's not a lot but it was a good boost). There are a couple of other sponsors one can choose from such as Hilton Hotels and American Airlines etc. Cashing out of miles is in amounts of 500 only.
Just wondering if anyone else uses them and what your experience has been so far.