Ann: Business Update, page-29

PS:
I don't think about TAM or any of that rubbish.

IMO it's all about judging how much of the expenses is actually reinvestment into growing the business. For ABY, that means looking at the marketing spend and the website R&D. Part of those expenses would be needed to maintain the current business, and the remaining part is driving customer growth. So I try to estimate how that splits up, and I think of the second part like profit that is being reinvested. (Note: the P/E based on that should be compared to a fair P/E for the same business when mature/stable, so that we are not double-counting the growth.)