Why would I subscribe to your e-mail newsletter that is just your RSS feed and here and there some special notes sent to my e-mail inbox when I already subscribe to your RSS feed? Sure, it makes your subscriber count go up, but it doesn’t really help me in any major way.
Sure, it gives you an opportunity to up sell me on some affiliate products or services you might have, but those things rarely help me with my blogging goals.
You should be happy that I subscribe to your RSS feed rather than punish me by making me get the same information two different ways so that you look like you have twice as many subscribers.
The race for subscribers is silly, and if anything, you are making people deal with both information overload and saturation sickness, which then causes them to unsubscribe to all things that they decide are no longer necessary.
Add value to my life, add value to my blogging, and stop trying to spam me with your content over a variety of different services so that you appear to have more unique subscribers than you really have.