Well it's normal happened on primedice

, i saw a person bet 9 btc per bet and 220 ETH per bet before.
The bet almost hit 30 billion bets, i guess there will a giveaway to people who can bet 30,000,000,000 like Stake 2-3 days ago.
It is normal big bet on such big gambling site like Primedice.
Big site, and big gamblers, it is a perfect combination.

The fact is the combination is a win-win situation, big sites tend to give secured, reliable gambling platforms, in security, and reliabilty to pay for winning bets, whilst big gamblers don't want to play on small, risky sites.
Because they don't want to lose money on small sites, that might turn into scam ones later.