A facebook question.How it is possible.?

[Hector]

People Talking About This is the number of unique users who have created a “story” about a page in a seven-day period. On Facebook, stories are items that display in News Feed. Users create stories when they:

like a page, post on the page wall, like a post, comment on a post, share a post, answer a question, RSVP to a page’s event, mention the page in a post, tag the page in a photo, check in at a place, share a check-in deal, like a check-in deal, write a recommendation, claim an offer...

So, it is not completly related to the amount of likes in your page.