What it is
The meta description is the short summary that sits under your page title in a search result. It does not move your ranking. It is the one sales line you get to write for the result itself, the text a shopper reads before deciding whether to click you or the store listed under you. Leave it empty, or repeat the same line on every page, and Google writes its own from whatever on the page seems to match the search, which is rarely the line you would choose to win the click.
How common it is
Just over two-thirds of audited stores (68%) give their pages a real description. The audit reads product and category pages, not only the home page, and checks that a description is present and not overlong.
Why it costs you
Two stores rank next to each other for the same product. One shows a clear line naming the product, the price, and a reason to buy it. The other shows a clipped fragment Google pulled from the page. The shopper reads both before clicking, and the clear one takes the visit even from the lower spot. The click you earned by ranking quietly passes to whoever wrote a better line. Across a few thousand products, that is traffic you are paying to rank for and then losing at the last step.
Check it in 30 seconds
Google one of your product names and read the grey line under the title. If it reads like a sentence snatched at random rather than one you would write, that page has no usable description. To see what is set, right-click the page, choose View Page Source, and search for meta name=”description”.
Read next: Ecommerce SEO: Turn Search Visibility Into Revenue
Run the free audit to see which pages let Google write their search snippet for them.