I'm on a 30 day trial of Contactually, a contact manager that seems to handle one important function only: reminding you to follow up periodically with people who are important to you.
On the plus side, it does a good job of importing data from my Google account and from a handful of social media sites, and by doing so the amount of manual labor needed to do something with it is kept to a minimum. New contacts are created by it watching your inbox.
On the minus side, its sense of creating reminders depends on creating "buckets" of similar contacts to be reminded on a similar schedule, and the process of putting a living, breathing, complex human being into exactly one bucket is difficult if not impossible to do completely. They try to make a game of it, which at least lets you speed through decisions, but it's still a difficult task.
Once you have someone in a "bucket" it pulls a few of them out of that bucket every so often and reminds you to follow up with them. You can mark someone as followed up via email or through some other method, so it will keep track of phone calls or in-person meetings or whatever if you need to.
When I used to use ACT!, once upon a long time ago, I was better at following up with people because I kept track of when I last contacted people. I'm always surprised that native contact managers don't have a field that they keep updated for "last contacted" that can easily be sorted and will automatically be populated from other things that the system knows. ACT! never made it into my Internet world successfully, but I still remember its ideas.
Contactually is interesting, in the way that every single new contact manager is interesting. The price point is $0/mo (for a cut-down version), $20/mo (for what I have now), and $99/mo/user (for an enterprise version that I have no interest in). At $20/mo I had better be able to point to $1000/mo in new value coming from this, and based on the experience to date, I can't say yet that it's worthwhile to me at that price point. But I like the idea - hey, let your computer unearth some long-lost friends to remind you to chat with from time to time! I'm just not sure that I couldn't get the same results by taking my contact list, putting it in a file, and then generating a random line in the file to inspire me.