The problem for business regarding junk mail isn’t just the cost of postage...its the printing and handling costs on top of that that are prohibitive. Businesses are beginning to figure out that if they can advertise via the internet they eliminate both the postage and printing/handling costs.
Now, about the drive-by traffic ~ how do you get to them? Those are customers who hadn't thought about the product you want to sell them, but there it is, in the advertisement you just had delivered to their homes!
So, yes, printing is costly. Not getting your customers' attention is more costly!~