My website had its own adsense account for 2.5 years with my home address (somewhere in Europe) until mid-last year when I moved to the UK.
I created a new adsense account with a UK address (payee name exactly the same as before), put the new adsense script in and made NO other changes to the website. In fact, the website stayed exactly the same for the last 4 years! I never set any geo-targetting anywhere, don't even know where to do that.
Result? The website now earns about 40% more than before the move (and that's happened consistently for the last 8 months compared to the previous 8 months).
The exact same scenario happened with another website I own, moved at the same time. It's earning consistently more than before the move with no other changes, though the increase is more like 10-15% more than before.
Can someone explain?