Are you in the business of selling your knowledge in a pre-packaged format? In this case you could be creating eBooks for direct sale, or perhaps selling video training from your website.
You could publish videos and your site members could pay monthly for continued access.
Alternatively you could create video based courses and sell them for a one-off price rather than via a monthly; subscription, or some combination of both of these pricing models.
Have You Considered A Membership Site?
In many cases a good way to approach this type of website is to create a membership site.
A membership site enables you to automatically take payment – via Paypal or credit cards – so people can join your site without interacting with you – and will pay you monthly for access to the expert information you provide.
If someone cancels their payments then the membership site can be set up to automatically terminate the person’s access.
We have extensive experience of building and integrating payment systems and membership plugins into WordPress. Please be assured you could not be in better hands.