Yeah but if a pirate would have not paid the full price why care? It is by definition not a lost sale, the most likely outcome is just an increase by one the player count
A: I pirated a game 25 years ago and played it after school
B: I didn't
which cases do you think will make me more likely to buy more versions of that game later?
C. You didn't pirate, but played because your friends were deeply into it, so you skipped buying lunch to save money and pay for the game (pirating was hard for this specific DRM). You bought it at a discount on sale (remember, the price isn't fixed?). That feeling of overcoming hardship and friendship fused into a very positive experience, making it 10 times more likely for you to buy the next version than in A. or B. The overall likelihood still was tiny because now you have a family and don't have time to play, so that and
D. Considering the amount of uncertainty (your game company will go out of business in 25 years) the value of your "more likely" is $0
And then much later being a university student, I had money of my own and have bought games I liked. Never pirated to save money. And you know, GOG came along, and I was thrilled having the old games from my childhood again as digital legal copy. With manuals and addons. I bought 20+ old DOS games I already knew. Better late than never.
Edit: missed a word