Hard to say -- In Apple's case, there are so many potential users it's worth Google's money to get their search engine as the default. However, Mozilla doesn'

Hard to say -- In Apple's case, there are so many potential users it's worth Google's money to get their search engine as the default. However, Mozilla doesn't have a massive userbase like that, which leads me to suspect that Google only pays Mozilla to stave off pressure form regulators who would otherwise accuse them of having a monopoly on browsers.