Facebook ordered an investigation into the company's actions in September, but according to uSocial's founder Leon Hill, the site has now sent a letter to the company claiming it has broken several laws, including illegally accessing the site.
But while Hill says the company will no longer sell "friends", it will continue its business of selling "fans" for marketing purposes.
"We have been dealing with Facebook regarding this matter and we have removed our friend-buying service, though we're not budging on selling fans," Hill said in a statement.
"We are well within our legal right to do so and despite the C&D we're not taking the service down."
"We're actually not too worried by this and we'll be ramping up our Facebook services in the coming weeks," said Hill.
The practice of selling followers on social networking sites has become more prominent over the past year, with a number of services now taking advantage of the trend.
The industry is playing on the wide-spread use of social networks and users' desire for large numbers of friends or followers, which is often used as a metric to determine a user's popularity and social merit.
Fast Followers, Twitter Promoter and marketing company Magic Shovels are three examples of businesses offering Twitter followers for sale, with the latter offering up to 100,000 followers for $US2,999.
But smaller businesses unwilling to hand over the cash can also get in on the trend, with Twitter Promoter offering 500 followers for $US50, or 1,000 for $US80.
Tweeter Followers offers a "VIP Service" by which users can gain more followers, while "Tweecha", which says it is specifically designed for businesses, promises 500 followers within seven days for $US29.99.
But it appears that uSocial, founded and operated by Australian entrepreneur Leon Hill, is the only social networking service offering Facebook users for sale.
But SEO and social media expert Jim Stewart says he'll be very surprised if the "industry" lasts more than a year.
"This is an odd industry and I can't see it lasting much longer. It only seems to have sprung up in the last six months or so. Twitter is about networking, and not about broadcasting and spamming heaps of followers... if they are here in 12 months then I will be very surprised."
"I'm going to be watching these companies with interest... because I don't think a lot of sites, specifically like Darren Rowse at Problogger, aren't focusing in the size of their accounts but on quality."
Stewart says these companies are taking advantage of a new industry, similar to companies which sold email addresses during the early stages of the internet.
"It's similar to that, and it's basically just selling lists. Whereas Twitter and Facebook are very personal mediums, so I think to have 100,000 is a bad thing as you can't interact with them at a personal level."
"If you're buying followers who are real people, then why do they want to join you? What's the point? If you're just advertising with your account, who in their right mind would opt in for advertising?"
Peter Fraser, partner at online reputation management group SR7, says businesses need to be wary of taking part in any purchase of social networking followers.
"Companies and individuals need to recognise the risks to their brand and reputation online. Before embarking on a social media strategy, enterprises need to audit their exposure and develop authentic campaigns."
Facebook has previously warned businesses to avoid growing their profiles by purchasing groups of friends.
"The value of a person that is tricked, coerced or bribed into being a Facebook friend or fan is extremely limited and may actually work against whatever goals the customer is attempting to achieve," it warned.
It is not the first time Hill has been approached by social networks. Last year he was given a letter by bookmarking site Digg asking him to stop selling "hits" that would make a news item appear on the site's front page.
Related Items :
