Many of my small business owner clients hear anecdotes where a business was able to use targeting to create a veritable "money machine". The problem is these scnerios are fleetingly rare, complete bullshit or only apply to a specific niche.
The anecdote often glazes over the thousands of wasted dollars spent trying to perfect the model and a hundred other details that factored into the success.
The good thing for most is that digital advertising is no less effective than traditional advertising. Even if there's little to no targeting, or no tracking in place it's not any worse than tv/radio/print.
I can count on one hand the number of clients in my 20 years of web work that have created a model where they dump money in the top, and are able to extract more out the bottom. In all cases it didn't last more than a couple years at most.
For any small business considering hiring an ad agency that claims to have mastered this model ask yourself this: Why aren't they doing it themselves?
I think now the move is to go after territories that the major brands/agencies are afraid of. Tik Tok? I don't know, but I would trust doing DIY and examining the real numbers, I used to sell agency services, I'd say anything to win business. And 30% of the time we actually overdelivered on my absurd promises.
Given that you were probably smaller and not commodity priced to move I guess that sort of "honesty" helped move it better if people could closer to try before they buy.
Maybe for the Fortune 500 / tech startup crowd, but I work for small / medium businesses and there is still a ton of ad dollars being spent with no attribution / tracking.
I will routinely setup clients with tracking tools, which then discourages them as they finally see what their digital ads actually generate in terms of revenue. Many stop their digital campaigns and increase their traditional tv/radio/print budgets or, fall back to running digital campaigns with no tracking.
AKA "Brand Awareness".