No
OK I just want to save you lots of money. Read Carefully.
DO NOT even think that you can generate second income playing blackjack in an online casino. Mission Impossible!
Reasons:
1) 95% percent of internet casinos shuffle cards after every round of play. That means that you can not count cards. So casino always has a built in edge of about 0.4% on average over players. This means that you will lose 0.4% of all of the money that you wager over period of time.
MONEY THAT YOU WAGER OVER PERIOD OF TIME is your betting action this doesn't mean that you will lose 0.4% of $200 which would be $.8, but means that you will lose 0.4% of every wager that you make. These are average values.
As you can see edge has accumulative effect and your $200 will be gone in no time.
Lets say you play with $200 dollars.
Let's assume that you are playing 4 deck game ,dealer stands on soft 17, double after split is allowed , double any two, In this game house edge is about 0.38%
Now let's say you play about 180 hands per hour and your average bet is $3 by the end of that hour math says that you should lose $2.05/hour
If you bet $10 on each hand playing 180 hand per hour you will lose on average 6.84/hour. This is rule of universe and you can't beat it.
These values are calculated on average (and they are law).
Now do not think that every time you play you will lose exact amount as stated above. If you lose you wil probably lose lot more. One hour is still short term.
You can win in that one hour, you can win $1000 for example (1:10 000)
but you do not have edge and it is all about having or not having edge. Keep playing after that win and after about a month depending how long you play you will lose every single dime because edge will get you.
Card Counters make their money the same way having an edge.
As I already told you can not count cards in online casino.
2) But But what if I double my bet every time I lose .....
.....I always make money.
To cut the long story short. Betting Strategies do not work They are disastrous specially Martingale (doubling your bet after loss). Edge Edge Edge will kill you, unless you have it.
This doesn't mean that you shouldn't play in an online casino.
GOOD LUCK
Play for fun I do not think that Online Blackjack can generate second income.