I would pay serious money to use their historical data. It's a goldmine for machine learning research, finance, market research, news, politics, etc. I'm sure anybody could find a legitimate use for that much data from a social network.
Instead, I have to hack together a way to constantly collect tweets from within the past 2 weeks or use 3rd parties to access their data in any sane way.
Sell me your data! I want to buy your data!