The patrons of Full Tilt financed my last year of undergraduate work.  
I bought in for $80.  I cashed out prior to the start of classes with $6,000.  It took about a year and a half or so, maybe 6 hours a week.  All it takes is a lot of discipline, and not going for the "big score".
I played for no more than 10% of my bankroll at any one time, depending on how many tourneys I was involved in.  Usually, I never played in a tourney for more than 2% of my Bank. 
These days, there are 100 different programs that scan the client, and tell the other players what your ROI (Return on investment) is.  Mine was stable at over 900% at all times, and I stopped getting any play at those tables when people had those programs.  Nobody called anything, and I would end up just grabbing blinds.  
Now I just play live games, mostly, when I have any time.  Still working on my PhD, after all.