Site Features That Can Increase Engagement

Social media share and follow buttons (AddThis.com)

Facebook widgets (http://developers.facebook.com/docs/plugins/)

Like button

Comments

Recommendations

Facepile

Videos

Slideshows

Photo essays

Infographics

Interactive graphics (clickable maps, etc.)

Online communities/blogs with active commenters

User-generated content campaigns

Rolling asks (“thank you for donating, now tell your friends”)

Mobile optimization

Location-specific features

Consistent branding across channels

Clarity of design and messaging