Every business I've ever bought anything from would like to send me an email newsletter every day.
Personally I love finding out about good sales but a vendor like Best Buy notifies me of at least 99 sales that I'd care less for for each one that is worth of my attention. The ratio has to be more like 5-to-1.
Ask "is this important to the reader?" and not "is this important to me?" or "is this important to my boss?"