Sounds like a good idea for startup. Archive someones social media, if they require it. Perhaps browser plugin which archives all visited pages with some filtering.
To me, startups are a little too flaky for this job. They have a pattern of deleting customer data when they fail, and the nature of startups is that they mostly fail. I'd prefer a tool I can run locally, or a larger established player like the Internet Archive.
I keep looking for a good long-term, low maintenance solution for storing, organizing, and sharing family data (photos, videos, stories, et c.) and haven't found anything even close to good enough for me to commit to it. It must be a Hard Problem, I guess. Or demand is low because everyone just relies on Facebook or whatever to do it for them.
I recommend taking a look at GNU Mediagoblin for collecting/sharing your personal media. It supports multiple file types, like pictures, video, audio, and text.
Multiple storages. One in startup, second on Dropbox, one local, another one in AWS Glacier. This way startup failure does not affect users.
The challenge isn't the startup. It's the not-shutting-down.