Estimates of elementary and secondary students taking virtual classes range from 500,000 to 1 million nationally compared to total public school enrollment of about 50 million.
Online learning is used as an alternative for summer school and for students who need remedial help, are disabled, being home schooled or suspended for behavioral problems. It also can help avoid overcrowding in traditional classrooms and provide courses that local schools, often rural or inner-city, do not offer.
Advocates say those niche functions are fine, but that virtual learning has almost unlimited potential. Many envision a blending of virtual and traditional learning.
"We hope that it becomes just another piece of our public schools' day rather than still this thing over here that we're all trying to figure out," said Julie Young, Florida Virtual's president and CEO.