Quick back of the envelope calc shows that RSH would have $336m recurring revenue per year via capturing 1% of the target market (350m asthmatics). Based on $8 per user per month. This revenue number doesn't include device sales or any other potential revenue streams from additional products or pharma deals.
Or breaking it down further - roughly 8-10% of the population are asthmatics
The company will have a staged launch in key countries - so some assumptions are required for market penetration. Keeping in mind CE and TGA has already been achieved and FDA is on the way
eg
% of 2.5 million asthmatics in Australia % of 6 million asthmatics in UK % of 60 million asthmatics in Europe % of 30 million asthmatics in US % of 1.44 billion population in China % of 1.4 billion population in India