Hey there, full disclosure, I'm the COO at Refersion* - we're affiliate SaaS, helping you run and manage your own affiliate program. There's a few SaaS companies using us (crowdcast.io, tribute.co, and others).
While I completely agree with Ahamed on using review sites (we use capterra), our data shows it's possible to have a profitable affiliate channel with a SaaS product.
As with most affiliate networks, 90% of your sales will come from the top 10% of your affiliate network. Thus, we encourage customers to first identify specific influencers on Facebook and Youtube that you'd like to associate with your brand before trying to launch your network. By having strong launch partners, your affiliate network becomes more of a co-branding play, which is much more likely to result in positive ROI.
I hope this helps! Feel free to shoot me an email, my first name @refersion.com if you'd like to chat more.