Google product ads are not placed like conventional ads, but by means of data transfer directly from the shop. Here the Google AdWords account is linked to the Google Merchant Center and the data is transferred to the merchant area with a CSV file. The CSV file contains all relevant data of the respective product, such as size, color, price, item number and much more. In addition, there are the pictures and the item descriptions. If you use a conventional online shop, the function for generating a CSV file for Google Shopping is often already available.

First of all, Google product ads increase the number of visitors to the shop. The exact classification into the respective category favours the buying behaviour, because the visitor does not have to search for a long time before he finds the desired product.Furthermore, the increasing number of visitors can have a positive effect on the placement in the organic search results, because well maintained subpages and product pages often rank with long tail keywords

Source: Google Shopping