I came across to this discovery when i was affronted with the problem of trying to communicate TWO sites on different domain/server and some parameters need to be passed. As you may have “Googled” it, you can’t do outright javaScript function call from your site to a partner site since it resides on different domains. It’s a violation of the Cross-Site Scripting W3C standards for it is highly probable for site security breach. To make the picture clearer, here’s the scenario. Take for an example your site caters a hotel reservation and you have a partner seller that also maintains a site for marketing. If you want to maximize you potential sales, you’ll opt to let your partner embed/include your reservation site somewhere in their site. See the diagram now? Partner site e.g resides in www.marketing.com and your site in www.hotelreservation.com , without directly accessing your site, a customer must be able to get a hotel reservation on you part...
my experiences in IT shared.