We see the world through our own eyes. But that’s not what we’re really seeing. What we’re really seeing are patterns.
We’re matching groups of photons to previous groups of photons we’ve experienced. It’s the same with hearing, smelling, taste, and feeling.
We’re born into the world with no experience other than the womb, plus what appear to be some basic patterns (loud noises, falling, and bitter taste detection are three).
As we gain more experience, our banks of patterns build up, and that determines our responses for the rest of our lives (until we become aware of them and decide to make changes).
To get through to a prospect or an audience requires a deep knowledge of their experiences so we can figure out likely responses and alter them if necessary.
On top of that, people do change – either through new experiences (eg. aha moments), or by choice. So what worked one day, may fail another (which sums up 99% of advertising).
Also, a test can work well, but fail when scaled (and more often than not). So when it comes to prospecting and promises, your only defense to the question “can you guarantee results?” is to say no, and explain that everything is a test. Any reasonable person will accept this, and when they do (and some do), you’ll find that person to be a joy to work with (just do the work and keep them informed every step of the way if you want to keep them long term).
PS. Anyone can guarantee lead generation, just not the cost or the quality (or life would be simple for all of us, there’s no magic bullet).