It introduces business psychology, for one. You get all this and more, for free: - An expectation of support which is likely based on the purchaser's subjectiv

It introduces business psychology, for one. You get all this and more, for free: - An expectation of support which is likely based on the purchaser's subjective past experiences in receiving support, rather than on what's available in your support section - Pushback from your new customers-who-are-always-right - Passionate and very specific suggestions for improvement, _for free_, from people who paid and therefore believe they are your target audience - A complimentary covert contract governing the vendor-purchaser relationship, to accompany whatever you previously made very clear, which they did not and will not read - A noticeable dilution of others' perspective on your personal values--"ah, they are just sharing that link with us because they make money off of it" These are just some of the possible outcomes... Which is not to say it's not worth doing, but there are lots of important factors.