Dear advertisers, so you want to reach _specific_social_demographic? Good news, I can tell you 500k people who have demonstrated 3 points of identification with that demo in the last 14 days and are minimum 5% likely to interact positively with a promoted tweet from a firm in your market sector.
You can really pull a lot of useful data on someone by just looking at their follow choices, self-identification, and reply/retweeting behavior. And that's before you add all the information Twitter maintains on things like profile views or video plays, or the consistency of entity identification in tweet content etc. I can give you very specific kinds of demographics like 'people who enjoy tweets about dogs and football but not cats or politics.'
This market already exists (I get spam offering customer lead lists every couple of days). I suspect most orgs of a reasonable size are already being bombarded similarly.
Augmenting these lists with Twitter's data might improve/expand the lists bur won't create much extra value imo, because the demand side won't change.
You can really pull a lot of useful data on someone by just looking at their follow choices, self-identification, and reply/retweeting behavior. And that's before you add all the information Twitter maintains on things like profile views or video plays, or the consistency of entity identification in tweet content etc. I can give you very specific kinds of demographics like 'people who enjoy tweets about dogs and football but not cats or politics.'