I have discussed why most direct mail is bad, and one of the two reasons I gave was that it is too often written from the wrong point of view - that of the writer.
Junk mail is like the pub bore.
Somebody you find tedious because they talk about things that interest them and not you. They don't have the sensitivity to tailor their conversation to fit you. It is boring. It could be boring because it's about something of no relevance to you. It could be boring because it is full of boastful puffery about somebody's product, which they find of riveting fascination, but which you have not the slightest desire to read about.