Trust + Effort = Success

By default most people would prefer to get success with no effort.
If you are promising results your starting point for bargaining is 0% trust and a willingness to contribute 0% effort, regardless of what results you promise.
0% trust + 0% effort = 0% results
The key to results
0% trust + 100% promise of results + 0% effort = 0% results
The most constructive way of increasing a person's willingness to increase their effort is to first increase their trust in you.
100% trust + 100% effort = 100% results

Diet pills and get rich quick schemes work on low trust but no effort and a promise of results- you don't.

If you are planning a sales pitch based on results first make sure you have trust.