This is not often the case as what you mainly get is bulk email from the List owner and paid advertisers. Mail from these lists often arrives as a surprise and you discover that when you joined a particular program you were automatically subscribed to the newsletter or mail list being developed by the owner of the program you joined. It took me the best part of a day to go through my mail and have a look at the benefits I obtained from all the newsletters I receive, and the mail that flows from opt-in sources. Late last year, I joined extreme mail - a decision I would not recommend to anyone. No thank you.
Discussion lists are a far better return.
These are usually moderated and have guidelines as to what will be accepted for publication. Click here to view the archive and if you like it, become a subscriber - it is free to join. Other Lists will be reviewed here as they are tested and reviewed. The focus of the List will be Promotional and Traffic Generation - Tips, Tools and Programs.