I wrote an early review of Contactually, and I signed up for their pro service after the trial period expired. I used the system for a couple of months, but have decided to back down from the pro version back to the free version for a while. Here are some reasons for that.
First and perhaps foremost, Contactually is relatively expensive at $20/mo. I looked at what I was spending (or not spending) on other internet services that I use and like. I don't have a Flickr Pro account, but I used to, and I could get a year of service for less than two months of Contactually. Similarly I could renew another year of Pinboard pro service for less than two months of Contactually. It's not that it's expensive in absolute terms, but relative to other things I want to spend money on online, it looks spendy.
Second - and this is as much of a criticism of my habits than of Contactually - I never really managed to get it to systematically unearth new people to contact that had fallen off my radar. Rather than provide an ever-changing set of new folks to prod me to reconnect with, it seemed to recommend the same people over and over. That was useful at first to be mindful of people a second time if I had passed them by the first time, but the net result was that there were fewer people than I expected that Contactually re-introduced me to.
I have an Android phone, and Contactually doesn't yet have an Android app. I don't think that's a deal breaker, but I'm hoping that they come out with something that's awesome - and I'm willing to re-up for pro service again in order to try it out if that's what it takes.
I'm still unhappy overall with the state of Android contact managers. I would have thought that everyone ever designing a contact manager would have an updatable field for "last contact date" that had some kind of easy to view screens to see how you're doing, and that would be smart about noticing phone calls, emails, text messages, and meetings from your calendar. Hey, you could do that even on paper rolodex cards! Contact management basics need to be better across the board so that your phone can prompt you on who to call next, a sort of predictive dialer for your life.