Don't fully understand the wagering requirement thingy

Hi all, I am totally new to online gambling and the one thing I can't wrap completely around my scone (head) is the requirements b4 you can withdraw... So if anyone can enlighten me I would be eternally grateful.

i understand that you have to wager 11 times or 20 times or whatever b4 you are eligible to withdraw (using certain machines.. from what i gather mainly the slots)... now..... if I start with a deposit of $20 and get $20 in a bonus does that mean I have to wager $440 (11 times) of my own money ? Are winnings along the way included ? Is this a one off thing when you first deposit or every time you make a deposit ?... And are there any other little hidden things I should know before I get seriously started ?
I've tried asking the casino's online chat help but either I'm too thick or they have exceptional evasive tactics.
I look forward to some help.

Cheers, jenny ( JMM)

hi jenny, its very simply.All casinos offer simkind of bonuses.We on this forum are in the bussines of taking advantage of casinos wellcome bonuses, or if you like sign up or match up bonuses.There are 2 kinds of wellcoming bonuses.Fully cashables and sticky ones.You being a newbie, we'll start at cashables.The cashable bonus means that you (once you meet the WR) can withdraw your own money and bonus+ any winnings(if you still got them). Now, whats the WR(wagering requirement)?
It means that you have to wage certain amount,b4 you can withdraw.Lets say casino offers sign up bonus up to $100. You make a deposit of $100,and imidiately get the casinos match up bonus of $100. So your bankroll is now $200.And lets say the WR is 20 times the bonus plus deposit. That means you have to wage 20x(100+100)=4000.
You may say 4000 its too much, BUT the beauty is that you actually play with their own money, since you got the sing up bonus.Your bankroll is $200, and if you play blackjack(as suggested on this forum) perfect strategie, youll probably lose some money.But by the time you meet the WR youll still have certain amount of their bonus which is pure profit you can now withdraw. The house always has advantage, so youll lose money, but remember its THEIR money so no worries.

Hi, Thanks for your help, it's getting clearer for me.
In a casino I joined , blackjack,  amongst others, does not fulfill the wagering obligation, they basically only allow slots do this, so I joined another  casino with this in mind with the least amount possible thinking to  get the wagering requirements out the way before I play the games i want to ( which don't help towards the wager requirement)...is this a stupid strategy ? or am I unaware of some key factor which will mess me up at a later date ?

Cheers,
Queen of newbieness
Jenny 

hi again, yes at many casinos playing BJ doesnt fulfill the WR, but here on this site you can find the casinos that allow BJ. Just search for the best blackjack bonuses, on the left of the page.