Hi sneak,
A couple of reasons - by paying for the service you are a customer and your desires align with ours rather than us wanting to use your data to make money - we will never sell it. You fully own your data - no big companies with complicated privacy policies. And we are transparent about backups and security - http://www.wired.com/gadgetlab/2012/08/apple-amazon-mat-hona... - our versioned backups don't allow things like the above to happen and result in the complete loss of data.
Hope that helps, please let me know if you have any questions either on here or at hello@columns.co.
None of those things sell me. I have a local copy of my data on my Mac, and I pay for the service when I buy an iPhone every year. I fully own my data now.