Is there any guidance on how to implement a widget like uShip (which gives you pricing based on delivery zip code)? I think it’s more than just embedding some HTML into the ad, since eBay forbids POSTing to another server, or popping up a new webpage, etc. Does uShip have a special relationship with eBay, or can anyone (3-rd party) develop these types of widgets?
Even more than that, is it possible to build a widget which modifies the checkout process? While capturing the delivery address, for Russian addresses I need to capture the delivery address in both english letters and cyrillic alphabet - for better delivery within Russia. Basically, if the user doesn’t input the cyrillic alphabet address (in addition to the english letters address), they cannot finalize the purchase.