What Makes a Pay Per Call Lead “High Quality” for Advertisers?

In pay per call campaigns, getting more calls does not always mean getting better results. For advertisers, call quality depends on factors like caller intent, call duration, location, traffic source, and whether the caller meets the campaign requirements.

What factors do you consider when deciding if a call is high quality? Are there specific metrics or qualification criteria you use to measure call quality and conversion potential?

Would be great to hear how advertisers, publishers, and networks approach this.