Internet Ads
Hey! There's a fine art to annoyance! Annoyologists get paid big bucks to figure out how many ads you can put on a web page before people will click to another site.
You see the non-content material taking up valuable screen real estate on other sites, like The Other Tropes Wiki? (If you don't, turn off Adblock, you cheap bastard.) Those are Internet Ads. They are basically like ads in print media. They allow money to come to a site, so that sites can operate without people charging us to use the site (or at least charging us less than they would have).
In its most basic form, an ad on the Internet is simply put in a designated spot. Two main differences between this and print ads are that money from the ad is partly based on how many clicks an ad gets, and that an ad will likely change if you refresh the page, especially when more companies are advertising on the site. Unfortunately, the pay-per-click model invites something called click fraud, where software bots or cheap labor is used to generate more clicks (and thus more revenue for the website). Project Wonderful strives to eliminate click fraud through its "Infinite Auction" system. Another problem for web-based advertising are pop-up and ad blockers, which interestingly prevents you from viewing the above site properly.
Another form of ads is through pop-up windows. Those are hated more than Uwe Boll. They not only are intrusive, waste memory and occupy task bar space (depending on your operating system UI and/or internet browser), but some have the gall to disguise themselves as alerts from your system.
Some ads take it to the extreme of being outright evil and using a security hole to install malware on your system. If you're using an operating system other than Windows, you can tell them because they're asking you to download a Windows executable. This is why adblockers are sometimes considered to be part of a computer's anti-virus suite.
Another form is the in-page pop-up, or lightbox. These are far more annoying, as they take over the entire webpage until you can close them, a more difficult task than strictly necessary since they don't use your operating system's standard GUI.
Internet advertisements are also one of the cutting-edge areas of research for annoying multimedia software, pioneering techniques such as embedded frames, animated GIFs, blink tags, autoplayed audio, java, flash, video, and flash and/or java-based video players. Needless to say, this tends to eat up enormous amounts of bandwidth (which mobile users often have to pay for) and cause compatibility problems (up to and including instant crashes) on pages that would otherwise present only meager burdens on the reader's system. Most people hate these type of ads.
Another area of intense research has been coming up with ways to actively circumvent a user's ad-blocking. It has long been possible to detect at least some of the methods used to block ads, and change the page contents accordingly. The usual use has been to Guilt Trip their users or even blackmail them into allowing ads by withholding content. (For example, at least one method of ad-blocking will produce this result on The Other Tropes Wiki, which will then point out just how much they're paying their contributors and demand you shoulder some of the cost.) And by the middle to late 2010s methods of subverting and remotely disabling a user's ad-blocking started becoming practical for at least some ad technologies. (Again, The Other Tropes Wiki has dabbled in pro-active protection of their profit margin.)
And then there's the whole question of websites and advertisers tracking and profiling their users in various ways. Some may well be illegal, such as displaying employment opportunities or housing ads to specific demographics based on age or gender identity. Others are merely creepy or annoying, like that one ad that follows the user from website to website. You searched for "pickles and ice cream" just once, and now every site you visit from that browser, network or device is showing pregnancy-related advertisements? Not cool. In the European Union, the General Data Protection Regulation 2016/679 requires sites disclose their use of tracking cookies, but this only yields weasel-worded disclaimers that the tracking is "to improve your browsing experience" with no clear way to opt-out or shut the intrusive trackers down.
Add to this the problems with sites censoring content that they fear may offend the advertiser, and the financial reliance on commercial sponsors becomes a Deal with the Devil at times.
This site has some interesting pages about ads, and how we resent them or ignore them. If its author were an annoyologist, he would deserve big bucks.