For most, this feature seems like a long time coming for Google. With most eCommerce systems now capable of complex micro-data and product feeds in real-time, it feels like product-listing-ads (PLA’s) have been lagging behind for a few years.
In the emerging Google shopping universe of preferred merchant (asking for shipping speed and returns data) it seems silly that Google was not holding up their end. If they are eager to look past product data data for reviews, shipping speed, and returns as ranking factors; you would at least think PLA adverting would be capable of live data feeds.
Well good new, today Google introduced Automatic Item Updates For PLAs https://support.google.com/merchants/answer/3246284?hl=en