Hard to say. I only know the salary data ends up at less scrupulous data brokers (e.g. ones that sell directly to advertisers, though perhaps TWN does this too, idk)

It's not the employers themselves that use TWN directly, but the payroll companies the employers use. Perhaps in your industry or at your particular choice for jobs, the choice of payroll software does not end up aligning with TWN? _All_ of my previous salaried tech jobs do use TWN (I had to call each one, when a background check company seemingly couldn't do it themselves)

It seems most payroll companies send data to TWN [0]. Though I'd question the quality and breadth of each data feed. I also haven't looking into the percentage of US companies who use payroll software from the big providers and/or do it themselves

[0]: this comment tree at https://news.ycombinator.com/item?id=41510103#41512326