Pay only 500 yuan to get 10,000 followers! Look how thin I have become after taking this brand of diet pills! Why every man stares at me after I took this brand of breast-enhancing medicine ...

Users of microblogging services are often harassed by such advertisements jumping out at them. Vendors are treating the social platforms as a great business opportunity and cashing in by selling virtual "fans" to make users seem extremely popular, publishing advertisements that can be circulated tens of thousands of times and even hiring hundreds of people to sway public opinion.

The lack of any laws or regulations to stop vendors setting up a range of shady businesses mean that microbloggers, as well as customers of the online services, may be cheated but have no one to complain to.

The "zombie fan" selling business is hottest among online services. "Zombie fans" can make users seem popular with a high number of followers.

The "fans" take no part in microblog discussions but merely raise the status of users.

On weibo, the fan-sellers promote their business simply by sending their contact numbers to users who may need to boost their popularity.

A zombie follower, or fan, costs 0.05 yuan at some online stores. By paying 500 yuan, one can immediately become a popular microblog user with 10,000 fans. The production of "followers" is simple. Vendors working in teams create huge numbers of new accounts with fake names and email addresses in a couple of hours sitting at their computers.

Many zombie fans have numbers for names, which are easier to register, and those accounts usually have no other information.

However, one online vendor surnamed Wang said: "Zombie fans are now out of date as other users may simply recognize that you purchased the popularity by reading the fans' names. We are now offering live fans, which are operated by workers to interact with you." Such a live follower may cost 0.2 yuan.

Many businesses use the popularity of microblogging to advertise their products. A microblog account may attract tens of thousands of other users by publishing pictures of sexy girls or funny videos. After the microblog account collects a huge number of followers, it would suddenly change and start publishing advertisements.

According to the website of an advertising company, to publish an ad on a popular microblog account which has over 750,000 fans may cost 600 yuan.

A company is also promoting its latest service - to forward certain pieces of microblog or support some voices as a way to guide public opinion. "We can invite celebrities to forward certain opinions so many others will follow," he said. It costs 1,000 yuan to 5000 yuan.

In December, China began real-name registration for nearly all microblog services. But as many "zombie accounts" were registered before the rule was issued, they were not affected.