I'm delighted that many Mac users find MacHeist a good value -- even my colleague Aayush Arya and is happy with his purchase. But I find MacHeist's new intrusion into Twitter space to be completely over the line.

What MacHeist has done is to create a "." MacHeist is encouraging its customers to Tweet that ad, in return for a free copy of Delicious Library 2 -- the media cataloging software for the Mac -- and Ambrosia Software's recently released game Multiwinia.

It's no secret that social networking sites like Twitter are becoming an increasingly effective way for businesses to reach their customers. I see references to Twitter on the news every night, and in the interest of full disclosure, I should mention that we at Macworld maintain Twitter accounts (@macworld and @macworldbiz) to keep our readers abreast of what's happening on the pages of our Web site.

But Twitter is, by its nature, an "opt-in" network. The people who follow Macworld's accounts on Twitter are there by choice -- because they want that information.

By comparison, MacHeist has induced its customers to abuse relationships, personal and professional, they've developed with other Twitter users.