The social media giant announced a new program on Tuesday that places shareable “moments” atop users’ Facebook (FB) news feeds in an effort to get them to discuss events happening around the world. And, Facebook is looking to add some holiday cheer to the new initiative, which it is launching with 18 custom holiday cards that are available for users to share online.

In the announcement, Facebook said its goals are to: “Give people ways to connect and share with friends during holidays and events; Help people discover fun and interesting cultural moments; [and] Celebrate moments in history that continue to make the world more open and connected.”

Starting on Tuesday, Facebook said, its users would see messages at the top of their news feeds wishing them “Happy Holidays” and inviting them to share one of the platform’s custom-designed cards celebrating Christmas, Hanukkah, Kwanzaa, and the winter season. Previously, Facebook has employed similar shareable moments to wish users Happy Thanksgiving or remind them about the “Supermoon.”

Facebook’s new initiative is the latest new way the company has tried to encourage users to engage more with its platform. And, while the announcement describes the launch as a “marketing program,” Facebook has denied that the space atop users’ news feeds could eventually be populated by advertisers. The company told TechCrunch that advertisers cannot sponsor the messages being rolled out as part of the new program.