True, but also, businesses have used "coupons" for a long time. I saw one article where this was described as "selling the same product at multiple tiers".

eg. if you're rich, you don't bother with coupons (in general) - your time is more valuable than clipping the coupon and remembering to take it. if you're middle class, you use the coupon to feel like you're getting a deal, but if you forget, oh well. if you're lower class, you wait for a sale and then use the coupon to be able to afford it at all.

Similar with ads - if you won't let me access your site without showing me ads (even with an adblocker) - I really don't need your product that badly. Sell to those who have a lot of spare attention or willpower to look past your ads.

I don't mean I click on ads - EVER - but they're distracting. VERY distracting. I mean, the few times I've had to use yahoo mail from a browser without an ad blocker, it was an unbelievably bad experience. (yes, I still use yahoo. I got at least one of those accounts right around the time "BackRub" was renamed "Google")