This is what they say on their website:
On the Yummly blog we feature the best food websites. These sites may have great recipes, unique insights, beautiful photos or something else we love. When we feature a blogger, we promote them to Yummly’s millions of voracious food-lovers on Facebook, Twitter and the web, and designate them as “Certified Yummly”. We also give each site an exclusive badge to show off the achievement.
Thanks Yummly!!! You made my day! :-)