Update: Sorry Guys. Looks like this offer is by invite only. Which means you have to be already a Groupon member, and must have gotten an email with the invite. 🙁
Groupon currently has a deal to Get $10 Gas Card for $4. Check your emails to see if you got the invite from Groupon.
If you are new to Groupon, sign up here to be ready for future deals like this one. 🙂