I had a day job for the whole time so it was not exactly a pressing concern, but it took me about 16 months for the first seasonal spike leading to ramen profitable, a year after that until it was a consistent thing, and about 4ish months after that until I am more or less "day job profitable". (As in, "this could be my day job".)

If you want to see the actual numbers, see left hand sidebar here:

http://www.bingocardcreator.com/stats