In general:
I guarantee your satisfaction with the quality of my products and the training material and resources.
But I cannot guarantee a specific outcome.

How you apply my training will be the greatest determinant in your results but certainly not the only one. Many of the factors that determine your outcome are far beyond my control. Here are a few examples, but not the only ones:

demand for your offer
pricing vs perceived value of your offer
the level of competition and number of competitors
your budget
your profit margins
ad networks system and/or policy changes
your history with Google/AdWords
technology failures:
404 page errors
wrong phone numbers
shopping cart problems
merchant account problems
email failures
tracking code problems
landing page quality
choice of and strength of your calls to action
relevancy between your targeting/landing page
tax law changes
state law changes
national law changes
international law changes
climate shifts
zombie attacks (this is the one that scares me most, if you want my two cents)
natural disasters or acts of terror, etc.

PS Despite a few humorous lines sprinkled throughout this document, I take my relationship with my clients very seriously.