Residential universities historically dismissed online education, but as society becomes more high tech, the option of pursuing an education outside a traditional university has been gaining popularity. Online education is a $10 billion-a-year industry, up from $2.5 billion in 2004, according to the "Postsecondary Education Factbook" that includes information from Eduventures, an education consulting and marketing firm. Enrollment for online courses is projected to reach about 1.7 million U.S. students this year, more than three times those enrolled in 2002. The number of online students represents nearly 10 percent of total students enrolled in postsecondary education nationwide, according to the reference book, released in the fall 2006.