"No different to Xero, growing the customer numbers rapidly by spending a lot on marketing and forgoing profits." No. I own a stack of shares in Xero and having done my work there can say BIG is nothing like Xero. Xero has real cashflow. They could cut off customer acquisition right now and turn in massive profits.
BIG on the other hand, if FC cuts off funding and BIG turns off customer acquisition the tide comes out and it'll probably just be a matter of time before they have trouble keeping the lights on. They are toast.
Xero doesn't have to find a lender for their clients to finance the payments to them. Xero's cashflow is all theirs - unrestricted to use for whatever purposes they need to, while who knows how much exactly of BIG's cashflow is really real cashflow that they have unrestricted access to?
"BIG are growing customer numbers rapidly by spending a lot on financing/sponsoring and not so much focusing on number of actual paying customers."
At Xero there is a focus on actual paying customers. Some might get a free trial period that costs Xero almost nothing because the of their business model as a SaaS provider while BIG incurs costs for every single customer, whether they pay or not because it costs money to make videos for them. I also don't buy the story about a customer rejecting a video and them being able to just 'swap' them out for another.
Xero has a much simpler business model with no need for them to find finance companies to 'sponsor' their customers to pay them.