When Sephora decided to launch their new website this past April, they made heads turn with "15 Days of Beauty Thrills" – an engaging sweeps that rewarded their loyal users for what they already do.

These large and mini "thrills" skyrocketed sales, web traffic and showed how leveraging your partners and properly utilizing social media can truly and genuinely engage consumers, and reaffirm their love for your brand.

http://mashable.com/2012/06/20/sephora-15-days/