Merchants with no leads data will be optimized for clicks

What happens if there are no leads to be had for ice cream in Alaska in winter? Do we just keep experimenting with leads data from the summertime, assuming we have that data? From other merchants south of Alaska or just try to spend the money and get most clicks?

What if there are no leads data at all for any merchant in the stack or across stacks - let's say this is a new BA altogether - do we experiment/make up Conversion rates or optimize for clicks until we get leads data?

If there are no leads data (calls or onsite clicks) for the merchant or aggregated merchant data for the BAs, then the account will be optimized for clicks until there is leads data.

We need a mechanism to switch algorithms from leads-based to click-based. This option should be settable in the UI as well.