Shopping campaigns are one of the best ways of showcasing products online. They allow you to show your customers how your products actually look like and the price before clicking on the ad. This results in higher qualified clicks since customers can compare different options more easily. The click-through-rates (CTR) also tend to be higher for Shopping campaigns than for Search campaigns when targeting the same buyers. There are a few things to consider though when you set up Shopping campaigns that differ from Search campaigns. This article presents the most common issues that often lead to a Merchant Center account suspension whereby no Shopping campaigns can be created in AdWords.
Your online store has to include a page where returns and refunds are clearly explained. Even if you don't offer returns or refunds, still state your policy explicitly. The page has to contain all requirements and timeframes regarding possible returns or refunds. If those weren’t accepted, you’d also need to specify this in your e-commerce.
To have Shopping ads running, you’ll have to add at least 2 out of these 3 contact details on your website such as a phone number, email address or physical business address. Having a contact form is not enough for this purpose.
Additionally, please be aware that certain items cannot be advertised in Shopping campaigns. Some of those are dangerous products (such as drugs or weapons), products with a trademark not belonging to the trademark owner, vehicles, services and ticket sales.
There are certain practices that lead to a Merchant Center account suspension. Most common practices are abusing the ad network, obtaining sensitive data without secure SSL server connections, or misleading promotions.
You can read more about Shopping ads policies in this link.