Honestly, there are people that will always want free stuff, and that just needs to be accepted. Free users can give feedback, can spread info by word of mouth,

Honestly, there are people that will always want free stuff, and that just needs to be accepted. Free users can give feedback, can spread info by word of mouth, and can also turn into paid users. A smart developer will try to use them as an asset - which seems to be the authors intention by offering promo codes.