The Yahoo deal failed badly in first year, as Firefox users who were shocked by the change of default search from G to Y overrode default back to G. This caused

The Yahoo deal failed badly in first year, as Firefox users who were shocked by the change of default search from G to Y overrode default back to G. This caused Marissa Mayer's Yahoo to bleed money, as rumors supported by Mozilla statements say the deal was fixed-payment-per-year, not traffic-based. IIRC searchengineland cracked Yahoo's 10Q to show the blood loss. We also know the deal bled money because of Verizon getting out of it in 2017, when Mozilla went back to Google. Firefox market share is now in the danger zone where Google can replace it with more Chrome promotion and still save on TAC vs. Chrome-eng+mktg. Also the danger zone where webdevs do not test in Gecko and break Firefox, even on such properties as AirBNB.