Re: Previous approach
There are two schools of thought in the ad industry about how to advertise effectively.
Let's call them 'Brand' and 'Performance'
Brand advertisers say you should broadly target the whole market segment with your dollar-dollar. Sure, do a bit of hyper-targeted stuff, but most of your money should be about creating some kind of awareness and positive feeling towards your brand, so that when people come to think about buying, they think of you among the 2-5 options most people consider. These guys are winning at the moment. Byron Sharp (How Brands Grow) and Binet & Fields 'The long and the short of it' are the go-to studies. They purport to show that over the long term, hyper-targeting doesn't create demand or grow brands, and they don't do a bad job of it.
The other school is the 'Performance' ads. The hyper-targeting of people based on lots and lots of data, with 'buy now' type adverts aimed to convert. It works, but generally when people are more or less ready to buy, to make sure you buy it from place X instead of place Y. In the short term, it harvests a lot of sales, but it's a race to the bottom for both privacy and sales: you don't create demand like this, you can only harvest existing interest. And most advertising agencies hate it because it 'fucks with the magic'.
The point of me saying all this, however, is to highlight that most of the ad industry doesn't particularly like hyper-targeting except in those 'buy-now' moments. And if you leave it to those buy-now moments, then your aren't doing your job of creating future demand. I don't think most of the ad agencies would shed many tears for the loss of behavioural ads.