Launching a product without creating the application, using google adwords for example could be a great a smoke test when you have meaningful metrics.
Reference
Ferriss, Timothy. The 4-Hour Workweek: Escape 9-5, Live Anywhere, and Join the New Rich. Expanded and Updated ed., 1st revised ed, Crown Publishers, 2009.
Highlights or timestamps
She set up a website with testimonials from her students and ran multiple ads through Google AdWords. And by analyzing the click and conversion rates, she could better gauge the demand and determine which search terms worked best.
— ^31837c from The 4-Hour Workweek