My global organisation is using Jive to successfully connect approx 80,000 employees worldwide. Jive has a very simple approach that is easy to understand and easy to use. Valuable business knowledge is now being shared and enhanced through this fantastic framework. Its a social business platform that understand how it needs to deliver a service to operate for business. There isn't 100% usage of the platform but that was never expected. Our usage rate is close enough to 100%, which says a lot about the ease of use of the product. The company has seen greater transparency and access to executives (they Blog) and a greater sense of being connected to "the company". New features in Jive have been well received. We have also integrated our communication platform with Jive so in affect it has become our default Intranet. Its where we go to learn, collaborate, think and grow.
Overall the product has delivered massive business gains for us and has even been tweaked to work as an Extranet in a separate instance. Its really the only thing that has been deployed internally that has become a runaway success within 6 months. So, basic uses are corporate communications, project teaming, topic teaming, idea generation, information and assistance, key links, exec engagement, just to name a few.