According to the 2012 annual technology market survey conducted by Eurocom Worldwide, “Almost one in five technology industry executives say that a candidate’s social media profile has caused them not to hire that person.” Previous Eurocom Worldwide surveys had found almost 40% of the survey respondents from technology companies review job candidate’s profiles on social media sites.

While we’ve all heard about the increase in companies checking the social media profiles of job candidates, this survey provides the first evidence that prospective job candidates are actually being rejected because of their profiles.

Are you using LinkedIn as an electronic résumé?

Tips to build a positive social media profile and avoid being rejected by a potential employer:

Facebook: Always follow the old saying about not posting anything that would make you embarrassed if it were published on the front page of a newspaper. Don’t use Facebook as a forum to vent on everything you hate about life, your job, someone else, or a company – talk to a friend in person if you feel the need to vent.  Some people recommend creating separate personal profiles – one for business and one for family and close friends only – but this is not recommended because it can be next to impossible to manage.

(Update: According to Forbes.com blog reader Jennie van Luptak, “creating dual professional/personal Facebook accounts is a serious violation of Facebook’s terms of service that could get you banned.”  If you are worried about what potential employers might see, Jennie recommends you “segment your friends using lists” because it allows you to “control who sees what – your supervisor gets to see the interesting news story you shared but not the pictures from last weekend.”)

LinkedIn: Better for job seekers than Facebook is LinkedIn because you can create a highly professional profile by using LinkedIn as an electronic résumé. This includes writing a succinct profile summary, adding your current job information, past job experience, education, skills, awards, and even obtaining testimonials from previous managers, co-workers, or direct reports. If you author a blog that relates to business or your work, be sure to include the URL information.  Then, you can encourage potential employers to review your information on LinkedIn.

With more and more companies jumping on the social media bandwagon, it only makes sense that searching social media for background information on potential job candidates will continue to grow. This will make it even more important that everyone actively manage his or her online persona.

Bottom line: Decide how you intend to use social media and to whom you will allow access (especially on Facebook).