I know this is a double edged sword, and I think this is going to be a longer post.
For one thing, mail order (which is comparable to 'bulk emailing') has been around for quite some time, and still has not died.
When it comes to email marketing, I think quite a lot depends on two factors:
a) the quality of the adresses
b) the quality of the content
To understand better, look at it form a marketing perspective: its easier to sell your product to someone who's interested, than to someone who is not. Also, if oyu 'bundle' the product with other services, and you make the sale of the product look like it isn't the main thing, you'll gain, at least in the long run.
I'll give an example. I am subscribed to a mailing list about photography. This maliing list, which has about 2-3k subscribers is focused on equipment form one brand only, and besides equipment reviews (what equipment for that situation), there's some talk about techniques (how do I do this and this, is this flim more adapted than that one). 'load' of the list is about 20-30 messages a day.
One of the subscribers of this list is also part of a large mail order company (spercialised among other things in photography). Often he gives advice regarding certain photographic items. He does not 'sell' anything, but with this advice he builds trust. People know: when I buy it there it is him who'll handle it, him i can contact if anything goes wrong.
If he weren't on the list he'd sell less.
The message is: think about the messages you send, I rutinely delete messages from unknown senders, with an uninteresting subject.
Well, I am ranting, I think.