I created an account with Yahoo PPC Sponsor Ad with market USA and Canada some time ago.

Under Tab “Administration” and “Master Account”, Market : United States and Canada is clearly stated.

Under Tab “Administration” and “Account“ , there is an item “Blocked Continents” with comments “Continents fro which you do not want traffic”

I thought my market is USA and Canada so I did not take any action for this function, though I was aware of this function.

Later I got a shock to find out clicks form USA/Canada are only 5 % and 95% are from ALL OVER THE WORLD and I wasted money for this.

I got to “Blocked Continents” and I blocked continents Asia Europe Africa South America Australia.
Yahoo told me I did the right thing to specify those continents, but they told me they cannot guarantee.
They are right.
I still have clicks mainly form Central American and South American countries and Mexico and occasionally Indonesia, India ,Vietnam etc

SO my estimate is still currently 70 % from USA/Canada and 30% from other countries.
Yahoo told me they cannot block 100% traffic from outside USA/Canada.

I would appreciate if real experts in this forum could enlighten me in plain English how country/market target works and why they cannot block 100%.
Also what about Google Adwords? Are they the same as Yahoo or better?
Herok - The Phantom of The Opera