Ask HN: For repeat applicants to YC, how should you measure the progress?

There is a question in the application which talks about the progress you have made. What do you guys think is the best way to approach this? Where I am confused is that the two major things almost all of us have worked on is 1/ Users and 2/ Product. When they are talking about progess, is it the work done/efforts put in, or the numbers/achievements? Or something else?

Any thoughts on how to best answer this would be really useful for all the applicants here.