[faizanbhat]

The fact that I worked in ad tech doesn't automatically make an advocate for ad targeting. I don't like being tracked either.

As to your question on why it's being done if it isn't effective, I believe there are two reasons for it:

1. A vast % of digital ad spend goes to a few companies that have personally identifiable information and very effective tracking. Google, FB. I did point of this exception in my comment. Frankly, these companies don't need to target you to be effective. They gather their richest data from your usage on their service.

2. As for the rest of ad tech: Media buyers at agencies tend to be fresh out of college grads. They don't fully grasp the capabilities/limitations of ad tech products, targeting effectiveness, etc. Agencies want to spend their digital budgets and not exclusively on FB, Google. They want to show that they're diversifying, innovating, etc. This IMO is how the rest of ad tech stays afloat.