Well, as a business owner I operate daily with the understanding that marketing is vital. But, being human I have to admit that, as a recipient of marketing, I'm not sure I 100% agree with the assessment that all marketing is worth the risk.
By that I mean, I can't help but feel a little lousy when I receive marketing from someone I already give money to monthly and they are seeking to sign me up as a new client. Even more fun is to be had when someone doing a joint-venture sends me mail addressing me as their customer (and I'm not) asking me to do business with someone they highly recommend (whom I am already a client of).
Maybe I'm the one being a jerk but frankly this leaves a bad taste in my mouth. It makes me not want to do business with the guy I have yet to do business with and it makes me want to do less business with the person they recommended to me who I am already doing business with.
How about this. You (we'll pretend your name is John) and I have already met and done some business together. Later, your friend (we'll call him Pete) calls me up and acts like we've met before, even though we haven't, and says you thought it would be a good idea for me to try your services.
Like I said, maybe it's just me. I guess it's a testimony to the scale I operate on that I expect marketers to at least keep track of whether I'm their customer already or not. I realize they are dealing in hundreds, thousands or tens of thousands of addresses at a time; but as a human being I guess there's always a desire to be in a place where "everybody knows your name".