To answer the orginal question, in addition to the bonus percentage, you need to factor in rollover requirement to measure the bonus. For instance, if it is 50% with rollover of 8 and I deposit $200 to get a $100 bonus, I need to bet $2400 to earn the $100 bonus. If I bet -110 sides at random, my expected loss is a 109 loss (2400x-.0455), so I would lose $9. In the instance of a 20% bonus with 4x rollover (which is common) and I deposit $500 and get $100 bonus, I need to bet $2400 to earn the bonus, and my expected loss is again $109 ($2400x-.0455), so I would have a bet loss of $9. It is the same thing for the most part.
I bet mostly horses, so in my case, I would look at each situation as a 4.17% rebate ($100 bonus on $2400 wagered).
As for BetRoyal in general, I also have a pending withdrawal from them. Late Thursday night, I logged on and requested a withdrawal. Firstly, it is difficult to find the withdrawal section on their website (it is just a little box at the bottom of the banking page where you enter the amount and click and button and you can't even specifiy the method). Apparently that doesn't mean sh.it b/c I get an email from them the next day telling me I have to call it in between 12pm and 5pm to get the payout issued. So I called at like 4:40pm, but it is too late because in BetRoyal land 5pm means like 5ish. So they tell me it will be issued Monday. So come Monday, no money by 5pm, so I call again and now it will be Tuesday. So I shall see. I expect to be paid, but it is still irritating. One of the best things a book can do for their business image is to pay promptly and without complications. My recent payouts from Carib, Pinny, and Oly have all been almost instantaneous. And Carib even sends me a little account memo telling me congratulations and that I am a great customer and that they love me. That is a really good feeling and makes me feel warm and fuzzy inside. But to have money stranded in limbo for days or even weeks is not a good feeling and I would be hesitant to deposit there again or recommend them. They are only hurting themselves. I only signed up with them because they were featured on TheRX, but they mysteriously and quietly vanished at some point. I don't like that.