Google recently posted to their Merchant Blog about upcoming changes for merchants. They also recently sent out an email about these changes to all merchants. An excerpt is shown below:

Starting May 3rd, 2011, we’ll require your product listings to include at least two of the three unique identifiers (Brand, MPN, GTIN).
…
While these attributes will not be required for your data feed to process correctly, they may prevent your items from appearing in Product Search results if not included.

…

Starting June 6th, 2011, we’ll also require your product listings to include tax and shipping information to provide buyers with important price information. This information will be required at either the account or item level (in the “tax” or “shipping” attribute) in order for your items to process and appear in Google Product Search results.

What this means

We’ve been getting a lot of questions about these upcoming changes. We know that ShopSite® is aware of these changes, and are working to incorporate new features and requirements in the next release.

UPDATE (5:30 PM ET): ShopSite has posted a Knowledge Base entry about the Google Product Search Changes.

However, merchants can easily add these requirements with their existing stores without too much trouble.

2 Unique Identifiers

With Google now requiring at least 2 unique identifiers, merchants may have to add an extra product field in ShopSite to be passed to Google. Brand is already a built-in option in ShopSite under:
Products -> Edit Product Info

(click image to enlarge)

So, you just need to add either a GTIN (Global Trade Item Number, which can be a UPC or ISBN for books) or an MPN (Manufacturer Part Number). Google has details on these Unique Product Identifiers.

Luckily, we recently wrote a blog post about adding UPC and ISBN codes in ShopSite.

That covers the May 3rd deadline.

Tax and Shipping

For now, the easiest thing to do is set a global setting in your Google account. Google explains this in their tax and shipping help docs. This will satisfy Google, and makes it a few clicks and keyboard taps to accomplish.

Currently, it’s not possible to auto integrate the per item shipping and/or tax values in ShopSite. This is due to Google requiring a more complex XML structure for these options.

If you need per-item level of detail, you may want to look into GoDataFeed. They offer a wide range of comparison shopping services that integrate seamlessly with ShopSite.

…

With the above tips, it shouldn’t be too hard to comply with Google and keep your products visible (and easily found) in Google Product Search.