We knew celebs were posting random Twitter ads to make some sweet side cash, but we never figured they'd be worth millions of bucks!

Curtis Jackson, aka 50 Cent, worked his Twitter account Monday to help launch the shares of a no-name penny stock company called H&H Imports, which he's also invested some major cash in.

Cent Tweeted:

    "You can double your money right now. Just get what you can afford."

Who could resist that opportunity? It definitely worked out for the rapper; H&H closed at 39 cents yesterday, up 29 cents, and boosting 50 Cent's 30 million-share stake by $8.7 million. Cha Ching!

Hey, when your Twitter account is 3.8 million followers strong, it can definitely be considered a lucrative side business.