http://www.bingocardcreator.com/stats/sales-by-month
I quit my job in March, and could survive on my fairly modest revenues indefinitely. (I have done some consulting on the side in the interim, which is nice, because it means I don't have to make any hard choices like "Proceed at maximum speed on the business or go home for Christmas?")
The next product comes out at the end of November or thereabouts. I am cautiously optimistic. I haven't accepted any investment yet.