I haven't messed with digg, dont know if I will or not. Not sure what benefit it would have on a NFL Football site, nor would I be good at asking people to "digg" my site, LOL.

COOP seemed to quit helping in SERPS quite a while back with google at least, really kept it for the referrals to the site, which were huge. Heavily banking on vBseo to replace those referrals with better rankings from internal links.