Mr Yushchenko's ongoing rivalry with Ukrainian Prime Minister Yulia Tymoshenko - a former ally - is another factor.

BBC: Strategy behind Europe's gas game

Politics is a family business in Greece: Costas Karamanlis, the New Democracy leader, is the nephew and namesake of a respected prime minister, and even reformers seem to find that the dynastic factor still counts.

ECONOMIST: Greek politics

Given the relatively small form factor of most smartphones, ads that are displayed during app usage are prime candidates for accidental clicks.

FORBES: How To: Advertising On An Intimate Device