Displaying social media links or buttons on your website dramatically increases your site’s exposure.

According to a BrightEdge study, Twitter share buttons give websites seven times the social media mentions compared to websites without a share button— which in turn leads to content being viewed by millions of additional possible consumers.

The study also shows that many websites are still not taking advantage of this enormous and cheap marketing opportunity, with only 53.6 percent of the largest 10,000 sites on the Web displaying social links or buttons.

“It’s clear that social sharing buttons can drive real social traffic that will inevitably drive sales, brand awareness or even affinity but it’s also clear that many brands are not taking advantage of this simple, cost free tool,” says Jim Yu, CEO of BrightEdge.

Currently, Facebook plugins such as the “like” button are seen on homepages of more than half of the largest websites, while links for Twitter are only on 42.5 percent of the top sites.