Internet marketing was started solely depending on email marketing in the late 1990s. Changes in search engines' indexing algorithms over the years brought in sweeping changes in the Internet marketing industry with social signals topping the current IM strategies.
Nevertheless, a few 'paid to read email' companies continue to persist but no new companies were reported lately.
List of paid to read email sites:
Let me just mention a few that continue to be mentioned in the GPT forums.
There may be more. Feel free to add to the list by leaving a comment.
Note: GPT sites are mercurial. They come and go frequently. Look for low or no minimum payout programs.