There are things people look for in a relationship like passion, love, sex, conversation and an activity partner.

Does attraction matter or compatibility? I would say both. If there is no spark, it's hard to get it and often times it doesn't develop and if it does it takes months maybe years. That's why sometimes best friends will become lovers.

However when your dating it's important to have some attraction and even better a spark on the first date. If can't see yourself kissing them it's going to be harder down the road if you become serious and sex comes up.

But ultimately passion fades and if your not compatible then it doesn't matter how attractive the other person is to you, it will end.

Education
Culture
Religion/ethics
Economics
Ethnicity

Most likely if you and your partner share none of these in common, the relationship is doomed to fail.

But hay if your looking for someone to just have fun with then these things may not matter. However be careful you don't want to brake someones heart.