Paid acquisition channels for workshops aimed at early-stage founders?

I developed a workshop for early stage founders. The feedback is amazing. However, the content is a bit of an "unknown unknown". i.e. Founders don't know they need it until they attend.

This makes it difficult to sell, and I'm on the verge of giving up (I always advise people not to fall in love with their own product, and to fall in love with the customer problem so I should listen to my own advice!)

But before I give up entirely, I've been working with a few freelancers to run some social ads. But I'm getting absolutely zero results.

Obviously the ads could be sh1t, the landing page a mess, and the workshop pricing wrong etc, but assuming that it's not all totally terrible, does anyone have any insight into good paid acquisition models for this kind of thing?