I'm not sure if .io has a disparate effect on users clicking on natural links. There few .io sites in the world (approx 100K according to http://goo.gl/hXm4i h

I'm not sure if .io has a disparate effect on users clicking on natural links. There few .io sites in the world (approx 100K according to http://goo.gl/hXm4i http://goo.gl/hXm4i) so there is no clear line yet. If it fits your project, is easy to remember for your customer segment, go for it.