For example, if someone in telecom industry creates a product that can only be sold to operators. The time it takes to convert an engagement can be upwards of 6 months. In such cases, what would be a good growth metric with which to measure your progress?
Now, we can chose not to call such companies startups but that doesn't solve the problem.
I am sure there are many knowledgeable people on this thread who can provide some insights here. Any pointers to read will also help.