Money goes into ads but no leads or sales appear — this is almost always a systemic cause, not "bad luck." Let's look at the three most common ones.
Cause 1: wrong positioning
The most expensive mistake is advertising built on wrong positioning. The product may be strong, but it's shown to the wrong person with the wrong promise. One client spent $6,000 with no leads; after fixing the positioning, $1,200 delivered results. Check positioning and the offer before increasing ad spend.
Cause 2: an unmeasured campaign
If CPL, CAC, and conversion aren't measured, you can't see where the money goes. The fix is to run several funnels in parallel, calculate CAC for each, and direct budget only to the funnel that works. Unmeasured advertising is the main source of waste.