Why?
Beating up third worlders or Eastern Europeans without cause probably will not increase your affiliate sales.
Might improve your conversion ratio ....

But first you should find good reason to exclude by IP CDIR block. This is a very unsophisticated way to do this -- look into GEO-IP solutions. You can block content -- they just get the page background, think the website is broken, then go away with their feelings unhurt -- it's all your fault LOL.

If they are worthwhile visitors, deliver your content in their language -- envelope the user agent language accept -- the browser language for the technically challenged.

You should only ban IPs that are scraping your content, referrals messing with your SEO, IPs causing problems.

Let me give you an example: On one of my affiliate cam sites, I have this visitor all the time from Poland that does not buy anything. He stays on my website and clicks to the sponsor's webcams for an hour a day! He's having a good time, and by doing so -- he is increasing my metrics; time on site, outlinks and direct (repeat) visitors. So, he gets something and I get something for my SEO -- my Polish friend with a hardon, LOL ... He helps my metrics for SEO search referrals.

Even though the sponsor incurs some expense from him, my sponsor gains from the high conversion rate SEO referrals that my horny Polish friend helps create, by his interest and loyalty to my affiliate website -- Google notices this One hand washes the other ...

Is the glass half full or half empty?