If you want to be grammatically very correct, it should be "Live sustainably", because it is an adverb. But especially in US-American English, people like to do without an adverb colloquially. Especially in the musical sphere. We also wanted to communicate in a uniform way: see BSH Film and Bosch Corporate Film, where "Live sustainable like a Bosch" is already used. For these reasons, we  decided to use "Live sustainable like a Bosch" for power tools too.