redirecting or am I cheating?

redirect

[kensav]

I want to have a new hosting account setup on my server but have the address be a subdomain from my customer's domain.

example: foo.example.com would point to my hosting: stuff.com

and everypage you click on keeps the foo.example.com/page.html address.

I can accomplishment this with a redirect from there site to my domain but is that a big NO NO for any SEO/SEM efforts I want to do later on?