How to Promote SaaS like WordPress Plugin?

In the same way as any other SaaS: relevant content, publishing in catalogs, posting on social networks, direct marketing...

facebook add can be like $1 everyday

• Reddit, FB groups and usual process of building traction by posting updates as you build the product (BuildInPublic)
• Also submit to Betalist.
• Some SEO.

Hey, I always like to reference to this but I think AppSumo is a grat place to start, get some initial traction and then use this money to experiment with paid ads. Finger crossed for your product!