It s not a scam, you just gave them your email address for free so they can bomb you with spam and resell it further. So no scam, just you being NAIVE, to avoid saying something more serious.
When will people understand NOTHING costs NOTHING, there s NO free money, passive income and similar shit.
funnily enough,they used to accept temporary emails at the start
I know people who took time and created ,literally, hundreds of accounts
when I calculated possible profit,I found out it would take a thousand of refs and 4-5 months to get minimal payout of like 200.000 satoshis
qoinpro had some weird "invest to unlock" monetisation system too,but I doubt anyone paid them for upgrades,so money don't come out of nowhere
think crazy is right,they either sold your emails to third party companies or had other,no less shady ways to earn money