Product Groups (previously called "Product Reporting Types") allows you to analyse sales in different ways than traditional category sales to help you understand how buying patterns are shifting across your products and then tie this back to how you run promotions and your production cycles.
For example, in automotive you could classify products by ease-of-fitment, for example Level 1 easy DIY, Level 2 more complex DIY, or Level 3 requires a skilled mechanic.
In clothing, you might want to report separately on Back-to-school products that are normally held in separate categories. In food, you might want to report on seasonal variations such as ice cream being chilled goods, or pizzas brought during sporting events.
You can set multiple product groups on each product for different ways to slice the data
e.g.
Ease-of-fitment: Level 1, 2 & 3
Seasonality: Hot weather, Cold weather
Purpose: Power Increase, Fuel Economy, Cosmetic, Safety
Setting Up Product Types
Go to Product Groups Manager and set up your groups.
The above screenshot shows the old "Reporting Types" name, this is now found in Admin > Product Groups.
Set up product groups on products via edit product under the Google Products Search box as below, or products import.
Reporting
There is a new report available under order Information Report called Product Groups to analyse revenues this way.
If you set up and use multiple product groups on products (e.g. ease-of-fitment Level1/2/3, seasonality Hot Cold, purpose Power, Fuel Economy, Maintenance) then when you run the report you'd select the 'product groups' that fit into the same grouping e.g. for ease-of-fitment pick Level1, Level 2 and Level 3 only. Otherwise you'd end up double-counting the revenue if other groupings are selected as the system would first pick up the ease-of-fitment grouping, then the seasonality grouping and add them together.