SEOPress does have an affiliate Program. You can get paid to send referrals to SEOPress through your special link. Here are the details on how to become an SEOPress Affiliate.
Long Tail Pro has an affiliate program with the Share A Sale Network that includes a two-tier (sub-affiliate) link as well. Promote Long Tail Pro and earn through their affiliate program.
All In One SEO is a Wordpress Plugin made by Semper Plugins. The All In One SEO Affiliate Program is part of the Share A Sale Network.
I’ve been using SEMrush myself for years. It’s an advanced website auditing software that allows you to track your website rankings, traffic sources, popular pages, backlinks and so much more. When I cut many of my costs in my real estate company during a shift, this one stood all the cuts! The affiliate program is recurring!
Spyfu is a popular keyword took where you can look up information about a keyword or topic that can lend to marketing decisions. The Spyfu affiliate program offers recurring commissions with 40% payout for life.