I have no set plan yet (the site is 1yr old)... SSLPing monitors almost 6000 servers daily, 250+ users... so maybe I'll follow your advice with some kind of support plan (I was thinking of donations)
Common piece of feedback I have seen in many donation-driven software projects:
Don't do donations. Do a support plan; even one as basic as "priority replies to emails". If a company wants to use your product, even if they want to pay, it's very hard to justify a donation whereas a support plan is far more readily bought.
