It's pure commercialese; nobody would really ever say it seriously. "Gusto" means "relish," as in "to eat something with relish, i.e., with great enjoyment." Also, of course, it means "taste" in Spanish, which may resonate with many Americans, since Spanish is widely spoken in the USA. It also echoes "Go for the gold" from the Olympics.
I couldn't actually tell you what the phrase means, because I don't think it really means anything.
"Go for the gusto" is a perfectly acceptable phrase, albeit one that has lost its popularity. "Gusto," however, is still fairly common in English. If you engage in an activity with gusto, you do so with energy, zeal, vim, and a cheerful or positive manner. You might, for example, eat a meal with gusto, which would mean you seem pleased with it and enjoy it.
To go for the gusto, similarly, means to act in a manner that will cause you enjoyment, rather than being timid, unadventurous, or conventional.