Google offers a variety of options to expose your products to potential buyers.  The primary considerations we're looking at here are:

Part of Zentail's service offering includes an option to manage your Google Shopping campaign, but we also have several partners who can manage Google Shopping campaigns as well.  Unfortunately, Google's Merchant Center doesn't handle multiple catalog feeds well, so this article will help ensure your Merchant Center is setup properly in any configuration. A primary question that you must answer is “who is going to send my product catalog in the Merchant Center?”  In general, there are three options:

For this discussion we'll consider Zentail and a third party, since webstores don't specialize in feed management.  The considerations we want to review are:

The Google Item ID is Google’s unique identifier for an item.  Feeds sent from Zentail use the SKU as this identifier.  Some other services use things like shopify_US_123456789.  

This difference can cause problems if you try to use two feeds.  For example, if Zentail sends SKU-A as an item ID and another service sends shopify_US_123456789 as the item ID.  The result is that Google will see these as two products (since the item ID is different) but disapprove them as duplicates since the other info is the same.  Similarly, Google's order history for a product is tied to the Item ID, so it's best to keep this consistent over time if you can.

Note: if both services use SKU for the item ID then the risk of having product disapprovals from two feeds is significantly decreased.  Then the primary consideration is:

Zentail sends all the relevant fields into the merchant center by default - including Google category, Brand, Product Type, and more.  If your third party service is using these fields then they can use Zentail's feed to segment the campaign as desired.  The only place this gets a little tricky is if they use the custom_label fields.  If your ad agency uses the custom_label fields, please have them discuss the considerations with Zentail's support team to ensure the best setup for you.

Regardless of where your Google catalog is coming from, Zentail should always be connected to both your webstore and Google to manage orders.  Ad agencies specialize in ad campaign management, but not order management.  Using Zentail ensures that the orders generated from Google will automatically flow through and be shipped on time so you can keep the momentum going.