Realistically I have found that there are many affiliate programs out there, but not all of them will be a success with the affiliates program website owner. It depends if you have a good quality looking site and a good quality affiliate program selling things that will interest a lot of people to want to promote.
I've found some affiliate programs don't get many good affiliates working with them and then others can get 100's or even thousands.
So realistically it's probably good to advertise your affiliate program just like you would advertise a website. Maybe try listing it in the affiliate programs directories as a lot of affiliates use them to look for new affiliate programs, you may not get any success or may get a lot of success, it depends if your program is what affiliates are looking for or some affiliates anyway.
Here's a handful of directories:-