How do you choose geographical markets to enter with your product?

It is sometimes quite difficult to make a qualified decision on which geographical markets to enter first and which markets needs to wait or even be postponed to “maybe later”. Which factors, in your opinion, count when it comes to market entry decisions?

Kindly let us know what is important for you when you are making a decision on geographic market entry.
Also please briefly describe your product to provide a bit of context.