I dare to pay by credit card

Absolutely. All payments are made via secure servers. It is significantly safer than using a card in a store or restaurant. Quite the opposite, payment by card is safer than bank transfers simply because if you are defrauded you complain to the card company.

They help their customers. The most accepted card is Visa, the next best being Mastercard. Many bookmakers only accept these two cards.
Mastercard has the advantage in that you can earn bonuses! If you play on Sure Bets and never lose you get a lot of money to circulate between different bookies. This gives you some bonus.