Take a look at this one:

http://www.ebay.com/itm/DEREK-JETER-SIGNED-NEW-YORK-YANKEES-100TH-A...

In fact, if you have the time go to ebay and do a search on "GAI Jeter", or "GAI Mariano Rivera".

Or just do a general search for "GAI" under Autographs-Original, Baseball-MLB, and check out the over 2000 items that are currently on ebay with their Cert.  Of course, many of them are good.  but the quantity of ones that are not are frightening.  Also, check out Tom Brady signatures, and the amount of GAI certified items that are typically there. I have not seen one authentic Brady with a GAI cert.