Welcome to WebmasterWorld Guest from 220.127.116.11
From what I can tell, your site is still fairly new - with most of the content just a few months old, is that correct? In cases like that, it can take a bit of time for search engines to catch up with your content, and to learn to treat it appropriately. It's one thing to have a fantastic website, but search engines generally need a bit more to be able to confirm that, and to rank your site - your content - appropriately.
Any other links are natural that people have put on voucher sites and competition sites from competitions and promotions we've been running.
Don't believe everything you read.