Seth Dillingham is encouraging Twitterific users to join him in Paying for Twitterific:

People who use this hack are stealing money from the Icon Factory: they didn't pay for the software, and they're not showing the ads.

I only remembered that I'd already registered my copy of Twitterific on the release of v3.0.1 back in November after I'd paid again just now ;-) But I'm happy to have stumped up again to show my support for the Icon Factory. I can't understand the mentality of those that try and undermine the efforts of others. If people like "Captain Marc" don't want to pay to remove ads then surely they can just stop using the app!