Oh, cool question! I’ve messed around with free spins a bunch. Sometimes it’s just a few bucks, but once I turned 10 spins into $50 after hitting a wild streak—total fluke, but I’ll take it! Your $30 sounds solid, though. I think it’s hit or miss, depends on the game. I found this site,
https://best-casinos-guru.net/, that breaks down how spins work—might give you some tips. My buddy swears by sticking to one game, says it ups your odds over time. What slot were you on?