If you are fish selling on the street, you are always yelling that you are selling fresh fish.
The same in the casinos, everything they can call themselves the best of all the best as long as people will lure to them gamble, their experience will speak and have to decide whether they will stay or leave and it will depend on their experience.
So rewards and high RTP will definitely catch gamblers' interest.
What if the fish that you sell is not really fresh? I don't think I can make a lie and besides, people will figured it out later on. You might get customers at first but you won't get any next time because people already learned.
I think it's better to be honest and say only the quality which you think you already have and can make you stand out among the rest. Maybe some casinos aren't that rewarding in terms of bonuses but by the time the person gambles on it, they get lucky and win. It's still possible for them to go back on that casino. I am actually like this. I don't totally focus on the bonus but I am only trying my luck on each new casinos that I see.