Google product get you a high rank. To have your site featured in Google products, you need to have a feed of your products. The title should contain targeted keywords. Description should contains keywords, but it should also be a soft selling description since it will be the only way you have to get a prospect to click on your product. Don’t optimize it only for search engines, optimize it first for human, then for search engines.

Feed should be updated at least every 30 days. One technique you can use is to shift titles regularly. Especially in special event and holiday. If you update your feed often, you’ll get better ranking. Submit new products frequently, at least every week. Create your own brand so you’re having no competitors in ranking if people want to buy from you again.

Ressources :

Google : How to sell on Google ?