Recently I put on ebay a couple HOFer signed baseballs I don't need anymore. I got an email asking where the COA is from on the baseball. I went and reread my description and nowhere did I make mention of a COA with the ball. I started collecting autographs long before a COA was heard of. Why would I want to pay someone for a piece of paper stating what I already know.

Personally I think COA's and LOA's are a crutch for the uninformed in many circumstances.

On the flip side I do keep everyone I receive. Afterall why throw away someone's work as long as it is from a reputable source.