Comment by stock_toaster

In addition to sibling commenters mentioning incentive-side (eg. paid to promote) considerations, I also propose both an "immersion" and/or "consent" component.

When you are dining, and are suggested food pairings -- I'm there to eat, so suggesting something food related from the same establishment, that may enhance my meal experience, makes sense and generally does not feel unduly interruptive. In a way, I consent to being offered additional interesting and available food items at that time and place. I would not find it acceptable if the waiter brought out a catalog and tried to sell me shoes or insurance.

In a similar way, I don't mind (and often even enjoy or appreciate) movie trailers at the beginning of movies. I'm there to watch a movie, and in a fairly non-interruptive way (before the start of the movie) I am presented with some other movies coming out soon. Nice. I consent to seeing them at the start of a movie, and they are relevant to the subject matter. I would certainly be irritated if they were hoisted upon me in the middle of the movie, or if they were about new cars coming out soon.

I have also at times been actively searching for something I need or want to purchase, but am unsure what exactly I am looking for or what are the best options. At that time I would certainly be more open and interested in seeing advertisements regarding the types of items I am interested in. I would "consent" to seeing interest based advertisements.

Summary: I do not enjoy being interrupted with advertisements completely unrelated to whatever activity I am taking part in. I only want to see them when it is related to what I am doing, AND when I consent to seeing them.