Shills -- the world's full of them.

A new study from UCSB explores the dark underbelly of shill services (PDF). In China, shills can be bought for pennies per review, comment, tweet, or email. Organizations operate on open sites, matching shill-seeking companies with individuals who have nothing better to do with their time.

Think of it this way. If you (or your competitor) could buy Facebook Likes and positive comments for pennies apiece, how many would you want? If you (or your competitor) is opening a new restaurant, how many Zagat stars can you afford? If you have a new piece of computer hardware, how much is it worth to get a dozen five-star ratings on Newegg?

All of the major crowdsourcing sites in the United States have systems to detect and (hopefully) deter blatant use of automated skewers: CAPTCHA codes, validating emails, even more sophisticated techniques such as monitoring how quickly you respond to messages. But those techniques fall short when there's a flesh-and-blood person sitting at a PC, working for pennies, and willing to jump through the hoops.

As the authors of the study say, "We have found surprising evidence showing that not only do malicious crowd-sourcing systems exist, but they are rapidly growing in both user base and total revenue."

Organizers enlist dozens or hundreds of professional shills. They orchestrate mass account creation (bolstering "XYZ Systems now has 100,000 registered users" claims), generate bogus ratings, post canned cut-and-paste positive reviews -- and follow up with screenshots of their successes. Money flows from the customer to the organizer, then to the shills. And it's very difficult -- if not impossible -- to trace.

The authors spent time looking at the two largest shill-organizing sites in China: Zhubajie.com, which is five years old, and Sandaha.com, which has only been around for a year. "Both sites are structured similarly, starting with a main page that links to a paginated list of campaigns, ordered reverse chronologically. Each campaign has its own page that gives pertinent information, along with links to another paginated list of submissions of completed tasks from workers. All information on both sites is publicly available, and neither site employs any security measures to prevent crawling."

You can see the results in the study (PDF). Bottom line is that a typical "task" pays 13 to 70 cents, depending on complexity. The authors tracked a total of more than $4 million in payments over the life of the sites. And there are millions of completed tasks.

The total number of completed tasks is showing double-digit increases month to month.

Turning the spotlight to the United States, the researchers looked at the for-hire jobs offered on Freelancer.com, ShortTask.com, Microworkers.com, and MyEasyTask.com. A very large percentage of the jobs advertised involve search engine optimization enhancement. Those sites draw short-time workers from all over the world: "Unscrupulous crowd-sourcing sites, coupled with international payment systems, have enabled a burgeoning crowdturﬁng market that targets U.S. websites, but is fueled by a global workforce."

Even shills are being outsourced overseas.

This story, "Cyber shill business is booming," was originally published at InfoWorld.com. Get the first word on what the important tech news really means with the InfoWorld Tech Watch blog. For the latest developments in business technology news, follow InfoWorld.com on Twitter.