Mention concept? How does it work?

Hi
I have difficulty in grasping the mentions concept..from what is it build?

I am trying a iphone news website for me and my friends www.jongensavond.nl , but as a mention,
I made one topic which has keywords, iphone, ipad, macintosh, app, jailbreak.
and I got as mention
Hack to Activate Office 2010 RC (RTM Escrow) With Free Product Key, that's not what I want!

thanks a lot in advance for your reply!
Greetings,
Martijn