Having a temporary position allows you to observe organizational structure, apply the information you have learned in the classroom in a real work setting, and develop strong contacts that could later be the tipping point of you landing your first big job!
In 2012 the National Association of Colleges & Employers reported that 60% of college graduates who had a paid internship prior to graduation were offered a job the summer after they graduated. Employers who pay their interns are more serious about the internship as it is often a recruiting tool. You will naturally develop more skills and bear more responsibility which will later make you more competitive and stand out amongst other candidates. Although, paid internships are very competitive and candidates who are selected typically have already held 1-2 relevant internships. The best rule of thumb is to begin interning early in college whether the position is paid or not and work towards securing a competitive internship the summer before your senior year.