You can't scale if your ads don't show up.
And you definitely can't scale if they're buried in position 5 or on page 2.
Search coverage is about two things:
Here's what happens when your search coverage is poor:
Shopping: Your products show up for a tiny fraction of relevant searches. When they do appear, you're ranked 7th or 8th in the carousel, below the fold on mobile. CTR is 0.3%. Impression share is 12%.
Search: You're only targeting 20 keywords when there are 200 relevant searches. Your ads appear in position 3-4 (bottom of page). Your absolute top impression share is 15%.
Meanwhile, brands with strong search coverage:
We approach search coverage in two phases:
Basic Level: Feed optimization, keyword coverage, Quality Score, and settings that get you better CTR
Advanced Level: Product duplication strategy lets you dominate the page
Let's start with the basics.