Here is my tips to avoid online shopping scams:
Take the time to research the different companies to find out how they work. Each have a little different set of requirements, and will ask for things done a little differently. It is important that you understand each and every companies requirements so that you do the jobs correctly. If you do them incorrectly you may not get paid for the work you have done, or get any future jobs.
Find out how each company pays. Some will pay you online, via your PayPal account, and others will send out a check after the job has been completed and verified. This is important to know how each pay out so that you know what is to be expected of them.
There are dozens of companies claiming that by paying them a registration fee they will send you job opportunities and teach you the steps to becoming a shopper. This may be true, but is also completely unnecessary.
AVOID THIS!The modus operandi is they’d ask you to evaluate a money transfer service. And after a few days, long after the scammers got the money, the bank will hold you responsible for repaying it. Ouch!
Here are some site where I get my online jobs:
Odesk and Elance: if you want to get paid because of your skills, web design, accounting, writing etc...
http://mystery-shopping-pros.com/ = get extra money, this companies are test driving advertisement from different companies. So they need your opinion about their product appeals including how their website appeals.
Google Adsense: All you have to do is create Free websites in 15-20 lines about any topic and post google ads in it.
transquotation.com/= if you have a third language. My mother is french and i am very good at it. I usually translate websites.