So 1000 startups, meaning 100 real new startups (I doubt startups that are already into payments using other platforms would switch), of which 10 or less startups could really do 50k in transactions, meaning 10x50000x0.027 = $13,500 (tops and not $1M) in loss for Braintree... But I am sure they are getting way too much marketing out for this.
The funny thing is that if you went in as the VP of Sales/VP of Marketing to the CFO of Braintree and said "Our exposure is just $13,500!" he'd beat you with a stick. The good news is the alignment is right here. The more in actual lost transactions fees that occur during the promotion the happier Braintree and the startups will be. As noted Braintree has its eyes further down the road.
Kristi from Braintree here. Admittedly, our legacy bank relationships left us as the middle man to their risk departments. This may be what you are referring to when you mention the "ludicrously strict risk team." This is no longer the case. Starting with the launch of our instant product, we brought risk in house. We are able to use our years of experience working with startups to develop risk processes that help us build relationships, not get in your way.