[0] https://travel.state.gov/content/travel/en/us-visas/tourism-...
[0] https://travel.state.gov/content/travel/en/us-visas/tourism-...
From your link:
> Travelers must have a valid Electronic System for Travel Authorization (ESTA) approval prior to travel and meet all requirements explained below. If you prefer to have a visa in your passport, you may still apply for a visitor (B) visa.
So it's not as complex as the visa process and can be all done online. The ESTA lasts for 2 years (as far as I can remember).
edit: spelling
Think of ESTA as an opportunity to search for you in terrorist & crime databases ahead of time, as doing it at the time of the entry is logistically hard.
If you are declined for ESTA you need to apply using the usual process at the embassy/consulate.
Overwhelming majority yes, exceptions are citizens of: Romania, Bulgaria and Cyprus.
From my circle of friends it seems like random chance, and because there is no reason given for the refusal one can only speculate. When I got my B-1/B-2 visa, my interview was very quick (I'd even dare to say closer to 1 minute). Whereas I have a couple of friends that applied for a travel visa and were rejected after being "interrogated" more heavily. When it comes to travel visas, I would assume they would mostly filter for potential illegal immigration, but all those I know that got rejected were pretty well "rooted" in the country.
There might just be the fact that getting an invitation letter from a company is considerably more important than receiving one from anyone else.
The Americans thought Turkey should run it to avoid them taking up a communist government
There's still un peacekeepers there keeping the conflict quiet iirc