Spam 1.0 was a blind barrage of emails sent to as many people as possible, hoping that the law of big numbers and a 0.01% response rate would make the economics work. You had to highlight your email address (jan at slidemagic dot com) in order not to end up on the global spam email distribution list.
Gmail spam filters pretty much solved that problem.
Spam 2.0 is the next wave. As a startup CEO I am bombarded by emails plugging developers and SAAS software tools. They are better targeted, have at least an offer that is vaguely relevant to me, and somehow get through the gmail spam filter.
And the worst part, the CRM systems that are powering these emails are incredibly persistent, they go on and on and on of apologising that I must be very busy and do not have time to reply to the email. It is a bit like the Crowded House song in the above video, after the CD track is finished (1990s...), the song starts again at 3:38 with "I am still here".
I have developed a new instant archive "knee jerk", as soon as you read an email with a familiar tone "Hey, we that as a startup CEO you are very busy but", you send the email to the archives.
My response would have been different if the approach was really personal and tailored. Like the one you should be using when fund raising for your company and sending teaser decks. But that approach is too costly for selling monthly SAAS subscriptions. My opinion: mass marketing via email will never work.