Ask HN: What tools do you use to manage contact with your users?

Recently, I've been thinking about how I can do a better job of giving admins at one of the websites I run better tools for managing their relationships with users and customers.

In my head, I'm envisioning a tool that's easy to feed information into about user activity and that also makes it easy for my admins to keep track of interactions and give context about a user when they have a conversation with them.

I've been looking at tools like Highrise for CRM, Tender Support, and a few others but nothing perfectly fits the bill.

So I'm asking, does anyone else out there use a particular tool or have a set of strategies to manage relationships and communications with users of your service?