The literal meaning is obscured with subtle sarcasm. This is often used to convince friends to try something really stupid or get people to buy things.
Fool: "Check out these bitchin' new Adidas kicks! I got them for $35! The salesman said they were Totally Legit too!"
You: "That says Adidos. With an 'o'. Adidos. Nice."
Fool: "Wha??? FFFFFFFFFFFUUUUUUUUU..."
You: "Hey, there's that van that says "Free Candy"! Once, I climbed in the back and it was FULL of gobstoppers! (lie) You should totally check it out!"
Fool: "Are you sure? Looks kinda shady to me."
You: "Oh don't worry, it's "Totally Legit"!"
Fool: "Oh, well OK, I'll try it then..." <Gets abducted>
You: HA LOL