Of course they offer interesting things because it is a marketing strategy, promotion so that their casinos are crowded with visitors. In fact we go to the casino to gamble 2 things we will meet, lose or win.
How many chances will you get for winning a lottery? In thousands chances you will have only one chance for winning. It clearly means that you cannot make any money in gambling. You will just waste your time and money in online gambling. Dont be fool and if you want to earn some money you must invest your money in some respectable field besides gambling.