SharePoint 2013 capabilities vs Yammer capabilities

Features	Yammer	SharePoint 2013
Inbox	Fully Supported	Not Included
Private Messages	Fully Supported	Not Included
Desktop App	Fully Supported	Not Included
Mobile Support	Fully Supported	Partly available
Integrated Chat	Fully Supported	Partly available
Recognition	Fully Supported	Partly available
Micro-blogging	Fully Supported	Fully Supported
Feeds	Fully Supported	Fully Supported
User Profile	Fully Supported	Fully Supported
Groups/Communities	Fully Supported	Fully Supported
Extranet Access	Fully Supported	Fully Supported
Social Search	Fully Supported	Fully Supported
API Support	Fully Supported	Fully Supported

Top-05 References for the same:

SharePoint vs. Yammer for Microblogging

https://www.nothingbutsharepoint.com/sites/eusp/Pages/SharePoint-vs-Yammer-for-Microblogging.aspx

Planning for SharePoint 2013? Make Sure You've Got Yammer on the Brain

http://www.cmswire.com/cms/social-business/planning-for-sharepoint-2013-make-sure-youve-got-yammer-on-the-brain-022084.php

SharePoint Social vs. Yammer - With User Interfaces, Looks Can Kill

http://www.cmswire.com/cms/social-business/sharepoint-social-vs-yammer-with-user-interfaces-looks-can-kill-022131.php

SharePoint Social Versus Yammer: What Makes Sense For You?

http://www.buckleyplanet.com/2013/07/sharepoint-social-versus-yammer-what-makes-sense-for-you.html

The future of SharePoint, Yammer, and mobile in the social enterprise

http://www.techrepublic.com/blog/social-media-in-the-enterprise/the-future-of-sharepoint-yammer-and-mobile-in-the-social-enterprise

The Yammer and SharePoint 2013 Approach to Enterprise social.

http://fr.slideshare.net/NoorezKhamis/the-yammer-and-sharepoint-2013-approach-to-enterprise-social

http://habaneroconsulting.com/insights/SharePoint-Yammer