Session Stitching (rootDomain)

Using this parameter, you can specify whether or not sessions between the subdomains of your site should be split up into individual sessions for each subdomain. Set this to the highest level hostname that sessions should be shared over ((e.g. example.com or shared.example.com). If you want a distinct session for each subdomain, leave it unspecified.

window.zipy.init('a4f13d18', {
   rootDomain: 'example.com'
});