Sauron tries corrupting Sam! He just has very little exposure time, and no idea what this weird little guy wants.

The ring is basically an inch from being dropped into oblivion and it is desperately trying to negotiate with a laborador retriever. It's expecting a wolf. It's offering a dark forest with tall deer and all the necks you can bite, and the lab's like, I dunno, that sounds kinda scary, I'm'a just do the thing and go home. It almost gets there. Being carried gently in the mouth of this tired barnyard animal, it offers... a lake. A really big lake. And the the lab's like, how big?, and the ring offers a lake the size of a sea, and the lab's like no, that's too big, but thank you. Ptoo. And then he goes home and only thinks of it in those dreams where his legs move.