Mystery Shopper

For future reference (and reference to the companies that I've used to work for.)

FirstlyI talk about those that I've used:

Retail Eyes

http://www.retaileyes.co.uk/uk/home/retaileyes_aboutus.php

GapBuster (Kicks you out if you don't touch the account regularly..)

http://www.xec.gapbuster.com/

And others that I know by name:

Grass Roots

https://www.grassrootsmysteryshopping.com/msw_pnlExtWelcome.aspx?

Retail Maxim

https://www.retail-maxim.co.uk//index.aspx