Of course, they won’t just give away the $10 bonus to anyone to try their casino. Even if OP didn’t mention it, I'm sure there are minimum requirements, like at least being Jr. Member or having Bitcointalk account that wasn't created just to claim the bonus. Like in your case, it's pretty obvious that you made that account just to get the $10 and try the casino.
There are even three newbies who want to avail the $10 I'm not sure how they even found out about this. lol For sure an alt account.
The casino representatives may not know that many alt accounts will try to get free money that will be distributed for their benefit, alt accounts are very likely to abuse this
They should make the rules clearer.
500 x $10 = $5,000 with this amount is enough to get reviews from more trusted members if they want to conduct a review campaign.
Hiring a campaign manager can give them good advice on how they can promote on this forum to the maximum and according to the budget that the casino has.
If toshi.bet has a good security system, it wont be hard for them to identify/catch multiple accounts who are trying to abuse the free $10 bonus. Even if there is requirement of minimum bitcointalk account level, it is still easy to be abused because it is not secret that someone may own many higher bitcointalk accounts. The best way to minimize abuse by multiple accounts is by checking the created account on the casino, of course having minimum bitcointalk account level will make it better.