Yes, they are legit. Incidentally, they're an Orbitz partner. But read the rules carefully. Most AA fares on Student Universe are student only (no faculty) and have age restrictions (unlike on some other carriers, who permit faculty). Also, I called Student Universe once to ask about mileage and the AA fare WAS mileage eligible, although it's safest to call each time to check the fare basis. They have a toll free number, but are not open 24/7.