What do these countries have in common???

Dominican Republic,
Oman,
UK,
Germany,
Poland,
Netherlands,
India,
Italy,
Spain,
Sweden,
Mexico,
Saudi Arabia,
Ireland,
Denmark,
Argentina,
Czech,
Norway,
Finland,
New Zealand,
Korea,
South Africa,
Austria,
Serbia,
Slovakia,
Egypt,
Croatia,
Russia,
UAE,

& Pakistan

Isn't it obvious?
At least one person from each of these countries visited YankeePhil in October,already.
I wonder if it was the PIP story??