Agreed as above, you need to address what you want to achieve from a communications perspective...and work from there.
I have not heard of Hipchat, there are a lot of these products out there so
the company should think about what products they currently have and how it
integrates similar to the company I used to work for buying Newsgator
because it integrates with SharePoint. If the organization has Salesforce,
Salesforce Chatter is a good addition as it would integrate with Salesforce
and I think Cisco has a similar solution.
When selecting any new product, it has to integrate with the existing
environment so it is not just about the new product. I hope this helps.
Best wishes, Madge
Before giving advice, it's important to know what is your problem with Yammer...
Check out IBM Connections
Wrong question. You need to explain your problem, then we can help. Start with the outcome, and work backwards. Never, ever lead with applications or technology.