I use Gyft app to buy things I would normally buy anyway. My go to places are Starbucks, Amazon, Whole Foods etc. But I buy things using the app instead of credit card. Gyft pays me points (3% for purchases using Bitcoin).

Gyft doesn't convert points into Bitcoin directly, but I just calculate how much money I saved and I buy Bitcoins on Circle using my saved dollars. This is how I grow my own Bitcoins.