While I am no big fan of Adblock Firefox extension for obvious reasons (Digital Inspiration is supported by web advertising), Stephen Manes makes a very good point:
The software isn’t perfect—for example, it can shut you out of sites such as Salon.com that insist on your sitting through an ad before proceeding…
Of course, if everybody used Adblock Plus, publishers (including PC World) would be out of business—until somebody figured out the next escalation.
But you know what? If ads annoy you enough to make you install this kind of software, I don’t think you’re the sort of person the advertisers want to reach anyway. Link.