Hell, this makes me crazy: suddenly we've realized, that we can absolutely not rely on query results we are getting with SeoToolsForExcel through AdWords API:
we get reproducible different search volumes data in dependence from how many keywords we query:
- if we query the one single keyword (we tested it up to 3): results are the same as we get in the AdWords Keyword Planner
- if we query 50 keywords, as on screenshooted test, we get for the same keyword search volume by 25 times higher, then if tested alone or through Keyword Planner.
Do somebody knows, what this means and how to deal with this?