Google started a beta testing feature in june, a local shopping inventory feature that allows merchants to render a list of current products they have in stock, so that the web users could conveniently find the products while searching.
According to the sources, Google has received a great response from the searchers and an influx of retailers who want to take part in it. Moreover, Google even announced that they were to open their documentation for potentially becoming a part of the rankings to the public.
Although, Google can not accept each merchant who wants to participate, at this moment, it would keep all the documentation on file for a further date. The important point the applicants need to consider is that they make sure that their store is listed on Google Places, afterwhich they will have to send a detailed and updated data feed.