I’m running a Google search ad.

I find that there are always far more “other search terms ”than “search terms” in the daily reports.

Google never tells what these “other search terms” are.

Why does this problem occur?

Not enough long tail keywords? But I have put dozens of keywords

Problem with keyword matching? I’m using phrase match

Keyword quality score not high enough? At present, most keywords have a score of 6-8

Or is Google just doing this on purpose?

How to slove this problem?