Or do it but without screwing current customers, use them as your free marketing force giving them even more discounts to honestly give you good reviews / recom

Or do it but without screwing current customers, use them as your free marketing force giving them even more discounts to honestly give you good reviews / recommend to their friends with a referral program. Instead of putting that money into adsense of fb ads, put into your current loyal customer base to help you grow it organically. Worked for PayPal, Uber, AirBnB, etc..