There is another way content can annoy the customer. The viewer of a web page may have no problem with an ad that has a pleasant appearance. But some types of ads have a user interface that impacts the reader negatively.
First there are ads that flash, especially ads that flash rapidly. Yes they get your attention, so much so that you will get the off the screen or cover them up. I have personally decided to purposefully not buy from a company whose ads contain this irritant. I would rather look at an ad that draws me to it because it is nice to look at rather than an ad that is irritating.
Another irritant are ads that cover the content you are trying to read. The customer will click on the x and get rid of such ads as soon as possible.
Ads that suddenly play audio, or any website that suddenly plays audio without having you click on an audio icon first are especially annoying, especially if you are on the web late at night and others are asleep. This is the same problem TV commercials have - it's not clear why some sponsors think they are accomplishing something positive when their ads are filled with loud noise, especially in the day of the remote control volume button.
I would also like to offer the opinion that it is better to have web content with less on the screen at one time, and larger print, as opposed to crowded content and tiny print. A dark background with white lettering is more confortable than a white background, which can have glare.
In interactive sites, if there are too many scripts and features it will take too long for the customer's packets to get back to your web site. On a cable network the downstream side is faster than the upstream side. Packets don't all travel the same route across the internet. So the user interface will have annoying delays and latencies. Keep it simple applies to web design too.
In the same vein, it's not clear why some website have a huge amount of blank space and small print, rather than using more of the space and making it easier to read.
There used to be more originality in website design. For some reason more and more web sites have migrated to vertical columns and small print and all websites are beginning to look the same.