When choosing an advertising agency to manage your google shopping, you have to be very careful. Lots of agencies claim to be google shopping experts, but they rarely have any experience managing shopping feeds with lots of SKUs. Be sure to ask what the maximum number of SKUs they have managed on Google Shopping and other channels like Bing Shopping, Facebook Dynamic Remarketing.
Can they handle product feed optimization for Google Shopping and Amazon?
It’s important to understand how they can help with the other engines as you have to really focus on all profitable channels.