So would lots of people
It's no big secret though, I was doing it in the 80's and 90's too. I bought and sold numbers before computing became mainstream,when sales offices worked from telephone books and business directories. It's no big secret, it's just marketing 101.
List start out rough and incomplete, they are great for call centres with auto-dialers. Once the NIS #'s are weeded out, the list is good for an inside sales team, but still has incomplete data, old employee names etc. After a good inside sales team has updated it, it's useful for B2B sales to upper management. Once THAT list is primed and tweaked it's good for C-Level sales and marketing needs. The data becomes more accurate and complete, the price goes up each time until it's an expensive and valued data collection.
