Soocial is a contacts sync service. They have a free level and a paid "premium" level of service ($5/month). I use Soocial (paid service) and I really like it. There is a major problem with Soocial however: the company was acquired in November 2011 by the French company Viadeo (blog post: http://blog.soocial.com/2011/11/29/soocial-has-been-acquired...), and the future of the service is unclear. You can still sign up for Soocial (I did!), and it works great, but this is a major worry for me as a customer.
I want to describe my experience using Soocial, because I hope that Columns will include all of the great functionality that Soocial has. The most important feature for me is that Soocial syncs my contacts between two different Gmail accounts (home and work), with Soocial acting as the "main" contacts storage location. I use this feature to keep my home and work contacts separate, while my iPhone has access to ALL my contacts. Also Soocial allows me to sync contact groups to my iPhone, which is not possible just using the MS Exchange server provided by Gmail. This setup allows me to keep a contacts "archive". I have a bunch of contacts (friends from college who I don't contact any more, ex-girlfriends, etc.) that I do not want to have on my iPhone, but that I do want to keep for archival purposes. Soocial allows me to keep those contacts in a central place (the Soocial web app) where they are accessible, but they do not get in my way day-to-day. Actually, having now described all the great features of Soocial, I've come to realize that I really really REALLY like Soocial.
I sincerely hope that Columns is successful and that I can eventually switch from Soocial to Columns. I would much rather be using a service that is being actively developed than one that seems to be coasting.
Question for the Columns team: What is your level of personal commitment to continue this service? Is it your intention to continue Columns as a service "forever", or do you intend to build up a great service and get acquired by another company?