They are advertising a phishing site. They send out mass messages in the hopes that a small percentage of the people will visit the site and either enter their account information or get their session highjacked.
This particular message is using a URL shortening service called ziroid.info to make the real url less identifiable as a scam. The real url is site claiming to be able to generate credits on your account. I won't post the real url to prevent giving them free advertising and prevent people from clicking on it. It's the same BS tactic scammers have been using for over decades.
Its pretty easy to tell this is a scam. Not only would a normal user not message some random person to ask a question like this (they would go to their friends or a forums like ours) but they are using a url shortner which is common for scammers. If you want to report spam or scammers to them their contact page is at
http://ziroid.info/contact.php. Though this services does look sketchy itself. The site is very plain and the URL is jibberish at least in English.