Hi Laura,
To be honest, I have no idea how VS handle their distribution personally, but a brand like Nike won't be at any wholesaler/droshipper. Anyone you find marketing so, pass on their URL so we can take a look at it for you. I have heard of occasions where Nike has been available through surplus avenues, but the branding had been destroyed.
The last thing a company like Nike want is to have their brand in the cheap bin, that just damages the value for them all round. So by controlling the distribution, they can control the value of their product.