Steven L. Johnson of Temple's Fox School of Business says sometimes the online blending of a person's main job and any after-hours interest might work, but it's probably best to keep a firewall between them. "It can get tricky," says Johnson, who teaches social media innovation. "We want to be around people that are well-rounded, but if our surgeon is regularly tweeting and posting pictures of himself skiing, you might start to wonder how good he is at surgery."