There
are thousands of signed items on-eBay,
although certainly you are correct in that it's not "most" people who are putting them there.
There are "professional" autograph dealers, but I think most people who have a signed item would want to keep it. I have a few autographed items, including a signed copy of "To Hell and Back", but strangely my favorite autograph is Ozzy Osbourne's- on a plain white piece of paper.
Signed items that you can buy are cool, but I think it's much more meaningful if the signature is a personal one.
The time I met Bruce Springsteen, it never even occurred to me to ask for an autograph or a picture, and I really don't feel like I need either. My memory is enough.
Often times, not very.
Or, they're just hastily scribbled without much thought. The only way to be 100% sure is if you actually see the person sign.
I agree. I think some celebrities have learned to differentiate the fans from the professionals, and act accordingly, e.g. refusing to sign certain items or for certain people.
I was once in Las Vegas with a friend, and she got very excited when someone told us that Pete Rose was signing autographs. She wanted to get one for her son, who is a huge baseball fan. That was until we were also told that he was charging $100 a pop.
I just thought that was disgusting. Needless to say, she didn't bother.