You can have fun in Second Life for a long time with no money. But eventually, most people want to be able to move up from freebies and buy some of those fantastic fashions in the virtual stores, or they want to own some land. That takes Linden Dollars ($L) and it takes money to buy $L!
(If you are lucky at Zyngo or have terrific content creation skills and earn all your $L in world, you can stop here. For the rest of you, read on!)
To get money into SL, you need to give Linden Lab a "payment method." This can be simply a major credit card. There are two major drawbacks to credit cards, though. First, not everyone has one! And those common workarounds like pre-paid cards and debit cards are not accepted by Linden Lab. Second, credit cards work in only one direction. You can use one to buy $L, sure. But what if you have a profitable Second Life business and actually MAKE money? You can sell your excess $L, and they go into your "$USD balance" in your Second Life account. But you cannot transfer dollars from Second Life to your credit card...they are not designed to work in that direction.
The solution is PayPal. PayPal is, arguably, the premiere way of transferring money on the Internet. It's easy to set up a PayPal account, just go to https://www.paypal.com/ and follow the signup process.
Ah, but we are not done yet. Linden Lab accepts only "verified" PayPal accounts. "Verified" means that you have gone through some additional steps on the PayPal web site to link your account to a Real Life source of money...either a major credit card, or a Real Life bank account. This verification process takes a few business days, and PayPal will make a couple of very small transactions to and from your designated funding source to verify that it works.
Now here is where we come to the heart of today's post. Linden Lab prefers that you use a major credit card to back up your PayPal account. This is because transfers from the card to PayPal to Linden Lab are near-instantaneous. Linden Lab refuses to wait several days while your bank transfers money to PayPal to pay for the shoes you just bought on the Marketplace. LL wants their money, and they want it NOW!
However, you CAN use a bank account as a verification method, and still use PayPal with Second Life. There is only one caveat. You must be careful to ALWAYS have enough money in your PayPal account to cover any charges from LL. That way, they never have to wait for their money, and they will be happy. And you, in turn, can have more control over how much money you "expose" for Second Life purposes, rather than risk your entire credit card limit over the internet.
Remember that a transfer of funds from your bank to PayPal can take a few days. If you are planning a major SL purchase, such as land, or if you already own a lot of land and pay a high monthly tier, plan ahead and make sure you transfer money from bank to PayPal in plenty of time to meet your obligations.
One last bit of advice: Use a unique password for your PayPal account. DON'T, for heaven's sake, use your SL password!
Happy virtual banking!