If you're using SyncWith to report on products and their sales (or product variants and their sales) then SyncWith only includes products (or variants) with non-zero sales during that time frame.
For example, if your store has 100 products, and you run a report including fields Product title and Total sales for the last 30 days, the report only include products with sales in the last 30 days.
Potential work around
One work around is to use SyncWith for Google Sheets, and create two separate reports, one to pull the list of all your products, and the other to pull products with sales, then the data from the two reports can be combined to show sales for all products. This same approach can be used for product variants too.
Example steps
Create a first report to list all of your store's products
Fields:
Product title,Product handleDate range: all time (so that you find all products)
Create another report to show sales by product
Fields:
Product title,Product handle,Total salesDate range: the last 30 days (or which ever time period you are interested in)
Merge the two reports using Google Sheets
Add a new blank column on the right side of report 1
Use a formula for this. new column to find the sales for the product from the other report
We recommend using
VLOOKUP, you can search in google to find examples of how to do thisUnfortunately we cannot provide help with Google Sheets and formulas