Rate Your Mate offers a quick 5 minute test that can help determine whether a relationship will last.

There are seven primary human domains that can be said to make up a person:
Physical, Social, Mental, Emotional, Spiritual, Sexual, and Financial. It has been proven that by looking at the difference across these domains between two people, you can get an idea of how successful a relationship will be. We've conducted a study that has shown that the sum of the differences between each of the seven domains can give a specific probability of a relationship lasting longer than 7 years. This discovery is what our test is based on.