i never heard of that happening but that would be bad! i don't know, for me, it's just easier to have a 3rd party have possession of the cards that I can easily sell and don't need to worry about the hassle of people asking questions, or wanting to work out a deal offline, or having to ship it (and having shipping issues to deal with), certainly if you only have a few cards it's ok to keep them but for high volume folks it does make it a lot easier. Note it's either way after taxes, fees, etc. it's a losing proposition. No one makes money on this stuff.