Dogs get the value of cuddling for its own sake. They like to snuggle up to you while you read in bed and while you polish your toenails and while you talk on the phone, and this is actually -- get this -- all they want. What's more, dogs are actually interested in whatever you are interested in. Jazz concerts by the lake? Awesome.
You can learn quite a bit about someone while you're dating. Foods they like, favorite activities, sexuality, intellect, family ties, openness, integrity, and a myriad of other qualities. But there's a particularly telling aspect of a relationship that's not obvious and it's a reliable predictor of its future.