Don Marti replied to my post in favour of direct marketing. I still disagree with him but I can see where he's coming from.
In brief the idea of carefully building a profile of you in order to select the product you are most likely to be interested in creeps him out, whereas I would just say it's trying to be relevant. If you regularly walk into a wine warehouse then you'll see a thousand different bottles of wine nicely categorised and be left to choose what you think is best, while if you regularly walk into a small independent store you'll be directed straight to what the sales assistant thinks you'll want.
Computers have been attempting to automate what that sales assistant does on a massive scale. I find that helpful, but I can see why other people would find it creepy. Ignoring the amount of effort involved or privacy for a moment, it is it means that if you surf a website about how to fold reusable nappies and then go to an online shop, it would show you the eco-friendly variety of nappies. People like Don would rather manually choose the eco category themselves than have a computer judge them and present a different experience to what other people receive. Fair enough.
Don also raised an interesting point as a brief aside which I've been putting a lot of thought into:
Is DM the equivalent of a cold call?
My initial reaction was that can't be right, you have to opt-in to DM when you never opt-in to a cold-call. But after thinking about it a lot I decided the parallel has some merit. If I open a web browser and go to a store to buy some wine then, well, I have essentially walked into a store. However if exactly that same store sent me an email telling me to go to their store because they've got some wine I would love then, no matter how carefully selected that message is and regardless of whether I initially opted-in, they have interrupted my day.
So I think he's right, DM is the store deliberately interrupting your day to remind you they exist. If you had to proactively go to the website in order to be shown the carefully picked wine then I wonder if Don would still object - is it the creep factor or the interruption factor? From a marketng perspective I know waiting for the customer to come to you is far less effective than interrupting them. If you want to make a sale to that customer then you somehow have to remind them that you exist and if you simply wait for them to come to you then your competitor will remind them that they exist first, and you'll lose a sale. It's an interesting problem - how do you stay top-of-mind without wasting everyone's time. Perhaps micro-payments are the answer? At least that way they're compensating you for the interruption. They have the nice side benefit of reducing spam's ROI too.