You cannot really expect to win steadily when you play blackjack online. You could win if you are a good player. If you are lucky, you could also win a lot of money to sustain you for a few months or years. However, you should not expect to have a steady flow of winnings by playing blackjack online.
At the heart of online blackjack's functionality is a technology known as the Random Number Generator (RNG). RNGs are complex algorithms used by online casinos to ensure that the outcome of each hand is entirely random and unbiased.