This deal has ended.
Update: Six Flags is having server issues and this is not currently working. Likely for today only, Six Flags Parks are offering one-day admission tickets for $10 each (limit two per order). Just head to the landing page and wait for the pop-up that reads "Twitter Ticket Offer" for the discounted price. You can either print the tickets yourself or have them mailed, though there is a $5 processing fee regardless. Tickets are valid through 6/30.