NateBishop, sports is a business, as we have heard ad nauseum. Jason Collins has brought business value far above his "sports" vaule alone. Sam is doing the same - although if he does not make the team the jersey sales will go down.
I don't think "mascot" quite describes it. More like a team drafting/signing a bench guy (or NFL equivalent) who is tremendously popular for some reason not strictly tied to sports, a local guy, for example. But gay players like Sam will not always be Collins type, that is, not impact players. I don't think that's true at all. Sam may well be an impact player on defense. And as more players come out we'll see more variety - scrubs, bench jockeys, stars, superstars. And sometimes bad guys who get in trouble and cause problems on teams. Because those are human attributes.