If that username is available and falls within the Terms of Use for WikiAnswers, then yes, you can register the same username as you use elsewhere. When using the same username on more than one site though, it is a sensible precaution to make sure that you use different passwords for each site.
go to amazon.com and sign up with an account and then go from there
No. You just "register" like an eBay account with your e-mail, name etc.
You can if you register with paypal. Register your bank account with Paypal and list your debit card as your primary card.
Ebay is a great site to sell just about anything you can think of. If you set up a Paypal account you will be ready to register for an ebay account and then you list the item with a picture and price.
You have to register for a PayPal account and provide the required information. Then, the account is activated. When a buyer pays for your item, the money is deposited in your PayPal account.
In the same way that you can sell any permissible item on eBay. You register as a member, create a seller account and then create your item listing.
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Firstly, you need to register to become a member of the eBay community. Once you have registered, you then need to create a "seller account". To do that, you can click on the Seller Account link on your My eBay summary page (if you see one there). Or you can use the Sell tab and part way through creating your item listing you will be required to set up your seller account. Or you can browse the help section and set up your seller account from there. Requirements vary for different countries, but typically, you need to provide your credit card details, your bank/checking account details and a verifiable phone contact number.
Google their name Ex. Username on Ebay
There is no charge for an eBay account.
To create an eBay account, navigate to eBay in your web browser and click on the blue "register" link at the top center of the page. If you need anymore help with the navigation or purchasing/selling features on eBay, you should check out this free online training site called grovo.com
Go to ebay.com and click register in the top right hand side. Otherwise try and buy or bid on something. It will force you into getting one.