Hi Sane4sure,
Had a quick look and there are a number of bootlegs on there. It is hardly surprising as a band like Genesis has been going for a long time with a big fan base. Fans will be interested in live work from the many gigs that they have done. Some people buy them as a momento of a gig they have been to. Some people buy them as they want as much material by a band as possible. I thought it was against ebay rules to sell bootlegs. It's easy to spot the bootlegs. Look at the many Genesis sites for a discography of general releases. A lot of bootlegs are on CDR, some with dodgy artwork. Or they are released on non-official labels.
There are many bootlegs of the big names in the music industry. Some are awful recordings, some are excellent. Depends where they were recorded from. I have heard some recorded from a cheap cassette deck to ones taken from the mixing desk. Prices vary.
I haven't heard any of these Genesis bootlegs.
SCIDB