How to read the result
A score is not a grade. It is a list of priorities.
The overall score is simply the percentage of checks passed. It is useful to know where you stand, but it is not the important number. The important number is the score per category, because that tells you where to start.
Under 50 on Measurement: stop here. Every euro spent on ads before measurement is fixed is a euro spent on a guess. It takes about a working day to fix and it is the cheapest intervention with a large effect in the whole store.
Under 50 on Technical basics: you have an indexing problem. There is no point writing new copy if Google cannot reach it or if the sitemap does not exist. It is also quick to fix, but the effect in Google shows up over two to six weeks, the time a recrawl takes.
Under 50 on On-page SEO or Structured data: you have content and markup work ahead. The effort is larger and the effect slower, but this is the part that compounds: a well-built page brings traffic for years. We write about this at length on ecommerce SEO.
Under 50 on Speed and images: you lose visitors before they see the product, especially on a phone. Start with the images — that is the best effort-to-result ratio you will find.
One thing we repeat often, because it is true: in most stores that ask us for help with expensive ads, half the fix is not in the account, it is in the store. That is why the same people run the ads and keep the store maintained — when we find something broken, we repair it instead of emailing a list of recommendations.