Sauron's Great Miscalculation

[Inziladun]

Originally Posted by Kuruharan

There is nothing in the books that implies anything other than an exploitative relationship.

I think Sauron's opinion of Orcs is well stated here:

And Orcs, they were useful slaves, but he had them in plenty. If now and then Shelob caught them to stay her appetite, she was welcome: he could spare them.

TTT Shelob's Lair

I doubt Sauron (or Morgoth) had any consideration of their servants, beyond their usefulness to him. Certain minions, such as the Nazgûl or the Mouth were favored with a high status in his hierarchy and, from the view of the Orcs, were seen as privileged, but Sauron would not have hesitated to sacrifice any of them if the stakes were high enough.