I took online classes through Georgia Virtual School in Highschool... Absolutely hated it, very hard to concentrate on work when all my work was on a computer with an active internet connection...Too easy to go read forums instead of working. The other bir thing is that you really had to do everything on your own, in college where I'm at now everything is explained in class and you can go and talk to your professor at any time for help. In the online classes we were basically given a curriculum and online copy of a textbook (just scanned in pages of a regular textbook) and left to fend for ourselves. If we wanted help we had to do it with E-mail which is a terrible way to get help. Then the online teachers really sucked, one math teacher responded to my inquiry about something by saying "That's not important." Guess what was on the test? Then when I took Astronomy the teacher didn't bother to do anything but give us links to Wikipedia articles and worksheets to fill out. Which I do like people respecting Wikipedia and I learned a good bit, but I'de expect more from state sanctioned schooling, even in the deep South.
So it will work if you are extremely disciplined and already know the material well enough you will be able to do it entirely from the textbook with little or no help. Otherwise your better off taking normal classroom classes, I know I learn much, much more in a classroom setting.
If it matters I'm an A & B student, only time I ever got a C was when I tried to take AP English online. In classroom college classes I made A's on Freshmen English 1 & 2, and have a GPA >3.5 during my year in Community College, I transferred to a University this semester and I'm expecting to get at least a 3.5 out of the semester.