Sometimes it helps to have examples. See below for other corporate brand promises---they may help you spark some ideas.JOHN DEERE
"I will never put my name on a product that does not have in it the best that is in me."UNIVERSITY OF IDAHO
In particular, I liked this one and its corresponding explanation:
“The University of Idaho is an intellectually-energized, intimate college environment for inquisitive students who want to join a legacy of leaders, thinkers and global citizens.”
The brand promise is not to be used verbatim as an external statement. Rather, it is a foundation, the overarching concept, on which our positioning is based.
Communications reinforce the concept of the brand promise through supporting messages.BP
“At the core of BP is an unshakeable commitment to integrity, honest dealing, treating everyone with respect and dignity, striving for mutual advantage and contributing to human progress.”TARGET
“We will connect business and community, affordability and great design.”Tagline
: Expect more. Pay less.
“Our promise to our clients and business partners is to provide and deliver Excellent Service at all times.”EKOVENTURE
“To ensure generations to come have the same opportunities to pursue adventure travel.”CITY OF BALTIMORE
“Baltimore is for people who like the excitement and vibrancy of a big city but don't like the stress, preparation and intensity that big city travel often entails.”Tagline
: Get in on it.