The freelance workforce is booming. Solution providers are taking notice, and jumping on board to hire independent workers for key roles in their companies. Even President Barack Obama touched on the topic in his State of the Union address this year. By 2020, Forbes reports, freelancers are expected to make up roughly 50 percent of the full-time workforce. It's a $1 billion industry expected to grow to $15.5 billion by 2020, according to Staffing Industry Analysts. Here are five reasons freelancing is something solution providers should keep on top of.