Thank you. While it's true that voting before others will give you more curation rewards than the people who vote after you, don't listen to that "thirty upvotes" number you heard. It's a pretty useless number. Who voted before you is much more important.
The curation system is designed to reward you for discovering great posts before they become popular, and disincentive voting for posts just because you know they'll become popular.
Good to know! It seemed like a weird number to check for.