It's a bit of an exaggeration, but maybe not by much. LinkedIn is already arguably one of the most successful professional networking social media sites. Now, with its announcement last week that it will start aggregating jobs from employers across the U.S., the company will effectively double the number of job listings it currently offers and will be positioned to take on the industry's leading aggregators – Indeed.com, SimplyHired and, of late, Monster. So reports TLNT.