I think the issue here is that Twitpic's business model is having people leave the main Twitter interface to take them to another domain, where Twitpic can extr

I think the issue here is that Twitpic's business model is having people leave the main Twitter interface to take them to another domain, where Twitpic can extract advertising money from the impressions. Twitter has image previews these days, which offer a nicer user experience and keep users on the main Twitter site. With Twitter hosting images itself, it makes little business sense for them to continue letting Twitpic make ad money off a feature duplicated externally.