Site navigation is one component that impacts usability across your entire website. Due to its range and placement on a page, navigation is also the most visible element of any eCommerce experience.
This doesn't mean you should pack your navbar with promotional content; it does mean you should use your navigation as an area to help visitors quickly & easily understand what you sell.
A brief glance at any of the navigation menus above will tell you that: Summersalt sells swimwear and other apparel, Zee.Dog sells dog & cat gear, Skims sells underwear & loungewear, Moment sells photography gear, and UrbanStems sells flowers & plants.
Rather than a dropdown titled "products" or "shop," use the space to show your range. Remove any links that don't go to products or move a visitor toward a sale. This real estate should be aimed at moving visitors through the buyer's journey—that starts with finding products that interest them.