Google Shopping Campaigns are a new way to create Google Product Listing Ads within AdWords. Although still in beta, Google Shopping Campaigns are basically a replacement for current PLA creation. Google hasn't noted that the new structure will ultimately replace PLAs as they are currently, but I would infer this will happen based on Google's update history, specifically the 2012 paid update rollout.
PLAs are based on the product information merchants send to Google through the Google merchant data feed. Google chooses results based on product feed information and advertiser bids. Advertisers create ads by segmenting groups from their data feed, grouping products based on performance and desired visibility.
Imagine Google Shopping ad creation currently as your social circle. You can be part of multiple social circles concurrently, and have different attributes when in each. Consider this visual representation of PLAs from the Google Shopping Campaigns Guide:
It's possible for different products to exist concurrently in multiple ad groups, based on different attributes.
The new PLA campaign structure is organized significantly different than your social circle. Imagine the new PLA structure as a pie. Shopping campaigns are structured so that product groups are cut from the data feed, segmenting remaining products.
Once you cut your data feed pie in half by creating product groups, you can only create additional product groups using the remaining pie:
Product groups in the new PLA structure are based on a breakdown of the data feed based on remaining products, so its important to choose which product groups your breaking out earlier during a campaign structure.
4 New Google Shopping Tools
1. Benchmark Click Thru Rate
Benchmark CTR is a default metric that helps advertisers stay competitive on Google Shopping by highlighting how similar products are performing. Google Shopping campaigns benchmark CTR notes what the average CTR is for products to help you stay on top of your competition. A similar metric is max cost per click (CPC), which notes competitor bids.
2. Impression Share
Impression share denotes the amount of times your product ads appear in search for relevant queries (as a percentage). Evaluating impression share will help advertisers determine appropriate product and product group bids for PLAs.
3. Products Tab
The products tab is a significant change for Google PLAs. Currently with Google Shopping, product information is accessible through the Google Merchant Center, which is not always accessible for all advertisers and merchants. The products tab displays all of your product information from the Google Merchant Center.
With Google Shopping PLAs, merchants can decrease visibility for products using negative keywords, downbidding, and by removing products from the data feed. Google's new exclusions feature allows merchants to exclude a sub-group of products from a product groups.
New Google Shopping Summary
New Google Shopping Campaign Structure is based on sub-groups from your all products group.
New Google Shopping tools help you spy on your competitors.