My impression is that most pitches that happen at that stage are simply growth rate followed by revenue projections, no real magic when you're seeing the growth that they are.
They have little to no revenue at this point and no current revenue streams that point to being able to generate anything worthy of a $2.5b valuation. I guess my point was that I'd like to know what revenue streams they are anticipating creating that would warrant such a high valuation.
The investors at this stage still don't care about revenue. The main question is whether or not they can flip the investment to some other firm later (that is to say, will the picture look rosy enough in the future that someone else will buy in at a higher valuation).
Revenue starts to matter in the last round before the IPO (if it goes that route). If the sequence ends in an acquisition, revenues won't really matter..