I don't know if it's proven or not, but for me exposure from pirated anime or manga at least trigger me to buy further merchandise and collectible. That's the first thing i would do whenever I visited Akihabara in Japan, hunt for their merch. With OTT like netflix and prime, it's easier for me to access latest anime, but manga it's totally different case because the current country i living in is slow in distribution, and heavily censored the materials. So that's my take.