Visa Card Rewards are putting my kids through college

Since along time ago I have been using my fidelity visa for everything under the sun, I have amassed a fortune in investing the rewards I have earned from using the visa. Every month I invest my rewards in FXAIX, and over the last 7-8 years It has grown to over $40,000…..just from investing my rewards into a single Fund….thanks fidelity for making it easy