Click tracking works today
clickt's click-tracking snippet reads the tracked link a viewer arrived on, counts
views, and captures the email from any opt-in form. Get it from Channels → pick a channel → Sales pages and paste it on your landing pages.
If you point YouTube descriptions straight at a Gumroad product page, put the snippet on your own landing page upstream of it, so the click is captured before the buyer is handed to Gumroad's hosted checkout.
Sale tracking is on the way
Gumroad's checkout is hosted on Gumroad, so it will not take your code directly. The way to record sales there is to send buyers to your own thank-you page after purchase and put sale tracking on it. That guided flow is coming. Until then you get per-video click tracking, and revenue follows once sale tracking ships for Gumroad.
Later: Gumroad Sale webhook
A direct Gumroad integration is on the roadmap. It will capture refunds and subscription renewals automatically, so per-video net revenue stays accurate over time.