I'm able to hunt a specific spot more than once for several reasons:

1.) I only hunt that spot when the wind is in my favor
2.) I sneak in and sneak out when I'm done(or at least think I am)
3.) I spray with a scent killer not to leave any ground scent when I'm gone

I start to hunt elsewhere when I start to see less deer or no deer. Also, I have multiple hunting locations. It's no sweat off my back if one location is not doing well... unless it was a previous "hot spot" I put my heart in to.

If you're seeing deer each time you are hunting the same spot, then you're doing something right or just getting lucky. I've hunted the same spot one morning then again the next evening... and then one spot one evening to hunt it again the next morning. I've hunted the same spot morning after morning or evening after evening many times. As the numbers reveal though, the more times you hunt a specific spot, the less you'll see.

To gauge it yourself, if you're seeing less activity, it's time to give that spot a rest.

iSnipe