Dog food trial samples

Do people know which companies will send out trial samples of their foods? I have so far received samples from Chudleys and Skinners and have applied for a sample from JWB. I would be interested to know if anyone knows of other brands who do this as it's good to actually see what you are getting before you decide on a brand to follow (and you can always use the samples as treats afterwards anyway!)

Burns and Royal Canin will also send samples
Also pets at home will give you samples of their wainwrights pet food if you have store near you.
Edited to say I've used them as treats before too

oh and Vitalin and CSJ will also send you samples, sorry keep thinking of more