What is the best service to use to promote a new affiliate program?

The best thing is to design a multi-faceted marketing campaign for your affiliate program that is unique to your company.

I would suggest submitting your affiliate program to the top 5-10 listings that come up when you search for affiliate program directory on Google, MSN and Yahoo.

Don't bother with the sites that offer to submit your affiliate program to 100+ affiliate program directories. There are maybe a half dozen that are updated, maintained and can actually drive any affiliates to you - those "services" are not worth your cash.

Instead, try testing a variety of keywords in the PPC search engines to promote your affiliate program.

Also, make an effort to attend affiliate marketing conferences to meet affiliates face to face.

In my biased opinion, nothing meets persona interactions with affiliates at events.

Of course, you should endeavor to optimize your affiliate program and make it the best in your category to best sell it.

And when you're communicating with affiliates you should be sure to know the numbers for your affiliate program and company, such as average order size, conversion rate and aggregate EPC for your affiliates.