All third-party integration with Tumblr occurs via a Tumblr application (an application defined at www.tubmlr.com/oauth/apps), and every application is owned by one and only one Tumblr profile. You could either develop and code your own service to operate your application, or you could use an existing service to act as your agent.
The SocialOomph service is the agent that acts as the operator of your Tumblr application.
This arrangement means you own the Tumblr application that posts to your Tumblr properties, and you use SocialOomph as the software engine to do that posting for you.
It holds the following benefits: