When you launch your course or business the best results are found in doing webinars. Now there will be a saturation of webinars at some point and they won't be as effective as they are now.
So, start now you will be a head of the curve!
There is a lot of expense in doing FB Ads and if you aren't careful you might be spending more than you make.
So it's imperative to have a formula to work from, so you need to know your ad spend but you also need to know your conversion rate.