Page Promo Post going to Friends

I have a business page and I currently have 696 Likes. I’ve gained them to a great extent by posting out an introductory post of what I’m about with a clip or image to pages I think might be interested. The people that already like my page should only be receiving on their page what I publish on my page, correct? I have two people that like my page telling me they’ve received 3 or 4 of they promo postings. Why when they haven't received them before? How do I stop them receiving them?

Poster :