There are lots of good affiliate programs related to genealogy, and lots of related keywords to attract visitors. This is a good solid niche for affiliate marketers.
Ancestry Affiliate Program
This is probably the most well known genealogy affiliate program. You may have seen their ads on television. However, did you know you can earn affiliate commissions by promoting them to your website visitors? You can! Here is your link to the ancestry affiliate program:
https://www.ancestry.com/lp/affiliates
Ancestry.com has a huge compilation of family history records, and a top selling DNA test that provides even more information about your family tree and history.
With the ancestry affiliate program you will earn 10% commission on AncestryDNA® sales and 20% commission for Ancestry® subscription sales.
Genealogy Freelancers Affiliate Program
To satisfy your website visitors that would prefer a genealogy specialist to do the heavy lifting for them, you can join the Genealogy Freelancers affiliate program here:
https://www.genealogyfreelancers.com/index.php?action=show&page=affiliate_description
These freelancers are professional genealogist researchers, and you can earn a 40% commission by referring your website visitors to them.
Military Genealogy Affiliate Program
For your website visitors interested in military genealogy, you can join the Fold3 military genealogy affiliate program here:
https://go.fold3.com/affiliates
Fold3 allows you to browse military records by war. For example, they offer sections on the Vietnam war, Civil War, revolutionary war, and of course the two world wars.
Higher Commission Genealogy Affiliate Program
For a good genealogy affiliate program that boasts higher commissions for affiliates, consider the OneGreatFamily affiliate program:
http://www.onegreatfamily.com/Affiliate/Affiliate.aspx
Their top affiliates earn 75% commission, although you would start out at the 25% commission level.
Newspapers.com Affiliate Program
You can also recommend that your visitors look up family history related articles in old historical newspapers. For that, you can join the newspapers.com affiliate program here:
https://go.newspapers.com/affiliates/
As you can see, there is a lot of opportunity to build an affiliate business in the genealogy niche!
Genealogy Keywords
There are lots of genealogy related keywords you can target to get visitors to your website. For example, a quick search in the Wealthy Affiliate keyword research tool turned up a lot. Here are just a few examples:
Surname genealogy
Genealogy family tree
Genealogy DNA test
California genealogy
You would create pages on your website/blog on those topics using the approach taught in wealthy affiliate to attract visitors. Make sure to recommend one of the various affiliate programs listed above on each page using your affiliate link. When your website visitors click on your link, you get credit for the referral and a commission if that referral buys something.
The California genealogy keyword also suggests you could consider a geographic approach where you create separate pages on your website dedicated to specific regions. For example Montana genealogy etc.
You would first check each potential geographic keyword in the wealthy affiliate keyword tool to see how many people search on it each month and how difficult it is to rank for. How to do all that is taught in the wealthy affiliate training.
To do well in the genealogy niche, or any niche for that matter, I highly recommend the tools and training offered at Wealthy Affiliate (free to join).