Obvious perhaps, but the most important part of someone’s social media account is not their past posts but rather their follower/friend/subscriber graph. A single purpose tool to mass export this graph to an email list in a surgical, opt-in way could be very popular.

You’d need their followers/subscribers to opt in for this to work. And you’ll lose most people in the conversion. Unless perhaps you incentivize them with a new or existing crypto to mass migrate. Maybe an inverse Groupon: everyone only gets paid if enough people do it.

The export tool itself will actually build a network effect once the first few exports happen. It would just have a lookup table that mapped (say) a Twitter username to an email address. After populating that once, the same user could export themselves many times with one click.

Another possible idea: scrape the public Twitter graph or get users to upload it piecemeal. Set up a public chain where you can claim coins under your username with a Keybase-style authentication mechanism. Perhaps one coin per real follower to incentivize the largest accounts.