Sure, if I bought actions from a photographer, its GOOD practice to go to that page and say "I love your awesome actions" as your page. That shows that real photographers use and love them
To post "I love your pictures like me back" well, that is just not right. If your page is named XYZ photograph I shoot dogs, kids and everything and clicking on that name takes you to their page, that is covert marketing using someone else's fan base and its rude.
Just because the internet was invented, does not excuse one of common courtesy. I mean really, would you walk into someone's studio and put your cards on their wall portraits and leave? Would you put a sign on their front window? Of course not. What is the difference of doing that and posting on someone's business page?
