Frequency of Sponsor Newsletters

Here's a useful discussion: in what frequency should sponsor's newsletters be sent? - GFY Webmaster Board.

I know some people view *any* newsletter as spam, but I do like getting emails from sponsors and usually don't consider it spammy, and this is saying a lot since I don't actually spend much time on promoting other people's programs so they don't really have much practical application in my workday. On the other hand, some sponsor mailings are better than others, and many of them are completely useless and sent far too often.

One of the things I *hate* is a particular sponsor who sends out far-too-frequent mailings with the header "Important News". Their last six mailings bear that subject line and only two of them could even be remotely considered important. Why not have the subject line reflect the supposedly important news? "New Site Blahblah" or "Closing site Blahblah" or "New Affiliate Signup Method"? The fact that they've been sending these every three or four days makes it particularly annoying.

Anyway, my vote is for once a month. Of course, I'd probably prefer once a week if the mainstay of my business was promoting other sites. But yeah, don't send anything at all if you have nothing to say and DEFINITELY don't send anything at all if your "news"letter is just a bunch of fucking ads for other programs, software, and other assorted bullshit.

I'm definitely interested in what other people's preferences are with newsletters especially in terms of frequency but also in terms of presentation; I've been sending all newsletters out in plain text, but I'm curious how many people prefer the fancy graphic-laden newsletters. Which do affiliates read more and which do affiliates skip over?