Impact and reach

When you are at this level of prioritization you are dealing with the stuff that is more important than keeping the lights on. This allows you to take more risk and you should try to move as light, lean and fast as possible. Per definition at this stage there should be few things that are considered top priority, because before you have impact and reach you need to secure that what is your product matters to enough customers.

A blessing and a curse at the same time you will have less stakeholders and less promises to deliver but you will also have less information. If you can, avoid overselling what you don't have yet, don't give people the wrong expectations. Since you will be resource constrained avoid trying to work on to many tracks in parallel, at this stage you certainly will not be able to cater to everyone.

For many product owners this involves marketing and finding a space where you can deliver something that has not yet already been delivered by others. An important source of information will be qualitative studies with future customers since you haven't yet scaled out a powerful platform for gathering quantitative data.