The economy is showing signs of life. And that means millions of people who have been stuck in jobs they hate will start looking for work. A 2011 survey indicated that 84 percent of Americans planned to look for a new job when the economy improved. And yet, the reality is that only a small percentage of them will be successful in changing careers. Here’s why.

1. Social Media

For all the talk about how social media can help you network your way to a new job, the real truth is: It can also hold you back from one. About 3 out of 4 hiring managers admit to doing a search on a candidate before interviewing them. Of those who do, more than 50 percent say that they opted not to have the person in for an interview based on what they found. Like it or not, hiring IS discrimination. Thanks to social media, the discrimination now happens even earlier in the recruitment process.