If you’re using an ad-blocker like AdBlock Plus (you should be!), and a page tells you that you need to disable your ad-blocker to see the content, it’s time to leave that page, and not return until they change their policy. Here’s why:
1) The most popular ad-blockers have “whitelists” that let content providers submit their ads for screening. If their ads are respectful–don’t install malware on your computer, don’t pop-up and cover the screen, don’t play loud videos, etc.–then AdBlock Plus and similar will let you see it! There’s no excuse for not being on the whitelist.  Are you a webmaster?  Click this link.  Now, you really have no excuse.
2) If an ad is not on the aforementioned whitelist, it’s because it’s a truly obnoxious ad, and/or the site’s owner isn’t a responsible citizen of the Internet. It’s literally unsafe to display such ads. In addition to being REALLY ANNOYING, they can install viruses on your computer/phone/device, steal your credit card information/identity, give your personal information to dangerous people, cost you hundreds or thousands in electronics repair bills, etc. There’s no good reason for displaying such an ad.  There’s no good reason for trying to make people see such an ad.
3) If you boycot pages that refuse to make their ads respectful and safe, you will force web site owners to make their content respectful and safe…which they should have, to begin with. Don’t give in. Yes, that includes, or your favorite “reputable” web site. It’s only as reputable as its content.  Be patient, and keep your ad-blocker on.
(You should also consider installing Web of Trust.)