After getting the end users email address, the marketer would send email marketing messages sometimes daily without an easy way to unsubscribe.

We send at least one email every sunday for our MaxBlogger Stories blog. It's a pure content blog where other bloggers share their success stories. I also usually send other helpful emails. Yes, I agree I send promo emails for other softwares/products but they are all reviewed for high quality and I suggest them as recommendation. That would be very valuable for bloggers who are interested on such stuffs. For the rest they can unsubscribe anytime from the newsletter without any obligation and continue to use our plugin.

By the way, who said there's no easy way to unsubscribe? There is unsubscribe link in each and every email we send. User just have to click the link and confirm. That's all. It's totally automated and instant.