AddThis - AddThis free website tools include share buttons, targeting tools and content recommendations help you get more likes, shares and followers and keep them coming back.
LoyaltyLion - LoyaltyLion is a data-driven loyalty and engagement platform trusted by thousands of ecommerce brands worldwide.
Shareaholic - Shareaholic is trusted by over 300000 brands, businesses, agencies, and individuals to grow website traffic and engagement 24 hours a day, 7 days a week.
Open Loyalty - 100% customizable loyalty platform with ready to-use-features gamification and loyalty features. Available in Open Source and Enterprise edition.
AddToAny - Share buttons by AddToAny, the universal sharing platform for websites and apps.
Antavo - Antavo is a contest app platform to grow and engage your audience. Viral contests, sweepstakes and giveaways to mobile, web and social.