I agree with everything that Faruk Ateş wrote about ad blockers and flash blockers, but I would like to add one more point, with which I presume he will agree; I think it’s implied by his writing by referring to certain advertisements as being beautiful and fitting with the content, but never explicified. My point is simple: the advertisements have to be compatible with the type of media I’m viewing.
I don’t block Flash as it typically crashes separately from Opera on Linux, nor does it seem to slow things down for me. I don’t typically block ads, either — though it is really annoying if one ad is making the entire page load slowly. However, I will generally close a page while it’s loading if I am annoyed by the ads. When do ads annoy me? Simple: when they do not fit the type of content I’m looking at. If I want to read some text, I’m fine with static textual or image-based ads. I don’t want animation, although I suppose it’s possible to change ads now and then without it being too obtrusive. Anything that utilizes Flash typically breaks these rules and comes with distracting animation. Worse, it often even comes with sound. It doesn’t really matter what I’m doing; as long as I’ve got my sound system turned on I don’t want any sound to come from my speakers that I did not explicitly ask for.
Now if I’m going to watch a video, like on Uitzendinggemist, then I’m perfectly fine with a video-based advertisement with audio.
After all, I’m requesting video with sound. A 10-15 second advertisement prior to actually viewing the particular video I requested is perfectly acceptable. Similarly, I welcome short audio clips or endorsements in podcasts if they help pay for the podcast. But don’t start playing such messages at random. Although I don’t frequently use Firefox for regular browsing, my favorite extension is StopAutoPlay. This isn’t just about ads of course and applies just as much to people who decide to stick background music on their site, or to start playing videos automatically (I’m looking at you, YouTube), though if I opened a video somewhere it’s usually not too hard to figure out where the noise is coming from.
What could be an acceptable form of a video-based advertisement on a non-moving Internet page would be something akin to YouTube embedded videos. These don’t autoplay, but you have to click the play button first.
Everything I said applies just as much to things that aren’t advertisements, but too many advertisements seem to be made as annoyingly as possible on purpose. I hope that nobody has ever gained any business from such advertisements. They sure haven’t from me.