If it were me, I wouldn’t bother taking a course. Yes, it’s a qualification of some sort, but I’m sure that an employer would be more interested in relevant experience – for example, shop work, where you’re offering face-to-face customer service.
I can’t see too many companies wanting to employ inexperienced applicants, so if you friend hasn’t got too many relevant jobs listed on his/her CV, maybe the course should be considered.