[beardyw]

> how often do I use products/app/websites from the other countries

Well, if the product is web based, the answer would be "am I likely to know?".

As to your market, you are well placed to do business in the Balkans in a way that a US start up is not - the opposite is not so true. Your appreciation of varying conditions in other countries is also to your advantage. If you make progress you will be less likely to have big companies trying to stifle you.

> Worst of all, I wasn't persistent enough.

You need to overcome that! I had big plans for a subscription based product. But early on I realised that growth was likely linear and cancellations would be proportional. As a mathematician I could see that would tend to a limit. But I persevered, and even though I was right I got a decent income from it until I retired. Modest growth beats none at all.