Alex Vidal, 27, began as social media manager in January at the 214-room Riverside Hotel in Fort Lauderdale. He’d been working as a social-media consultant, after mastering the craft mainly on his own. He started in online. Dance, dine, and play all trip long at Borgata Hotel Casino & Spa in Atlantic City, NJ! Can’t make it to the shore? Play online with our casino and poker sites! Independent hotels…