Getting a user to do _anything_ on your site is difficult.

I run a SaaS product that has closed sign ups. I get inbound email asking (sometimes begging) for access to the service. I follow up with their usecase (make sure they are a good fit, I get a lot of abuse). They respond with a seemingly good fit. I generate the account and give them access and they never log in. This happens way more often than I would like.

It's so bad, I started to wonder if there's some kind of underground market for selling accounts. In the end, people are finicky and you can't predict anything they will do.