Originally Posted by AaronM

Bingo parlors are awesome for the Granny niche. Sit in on a few games and listen to the old bags getting jealous of those winning. They love to talk about their families and how they wish they could do more for their grandchildren. Once you have established them as a "bingo buddy", they will be open to your business proposals.

You could try retirement homes as well but the staff usually catches on quickly.