I don't know. Social media usually work through brief exchanges, so we can exchange recommendations and references - as we do on Twitter to reference useful websites, for example. But what it takes to improve the quality of courseware takes much richer forms of communication, I think, than social media offer. It's a bit like asking what the telephone could contribute. It's not exactly nothing - any form of human communication contributes something - but it's not especially well adapted to the kind of communication that courseware improvement needs.