How to target based on country

I want to display CPA banner ads for US traffic and Adsense for rest of the traffic. Help and suggestions are very much appreciated, thanks guys

You can probably put a script in to your site to look at where the IP of the visitor is coming from. If the IP is coming from the states then you're CPA banner will show, else it'll be only Adsense. I guess that would be the logic. You'll just need to find a script or a programmer that can do that for you. But it's doable.

mate, you should check free/not-so-expensive ad servers. if your campaign is not longterm, put an eye on Epom ad server
I've jumped into it few days ago and was blown away. There are TONS of targeting features, not only geo, but also custom (behaviour) targeting, targeting by device, type of traffic etc

You can sign up as a Publisher and enjoy full trial for 2 months, it's absolutely free. but as for me, I don't mind to pay some $$$ to optimize my campaigns and get more revenue in the end.

agree on Epom. you can target cpa banner for US and adsense's banners for other countries with few clicks, and it won't cost a buck (for 60 days, but if you serve less than 250k imps monthly it's free forever). what's more interesting - they provide quality support even for small publishers that likely won't bring them much money. maybe it's because Epom is new player, who knows

You can just get yourself a script that redirects based on the country of the IP.

They're available all around the internet.

if you using wordpress should be plenty of plugins made just for that.

if not use a standalone script you will have to google.