You have to treat your dating profile as an advertisement; you are, after all, selling yourself to others.
This means that you have to consider your market, what you’re looking for and what makes you, specifically, attractive to others.
One of the advantages of online dating is that you are capable of carrying on several asynchronous conversations, fielding responses from persons X and Y while also sending out an introductory message to person Z. Focusing on one single person – even if you’re at the “meeting in person” stage – puts far too much importance on them and makes it sting worse if it doesn’t work out the way you’d hope. Everyone has heard it a thousand times before they saw your profile and they didn’t believe it any of those times either.
In the great chain of credibility, being told something is the least believable.
We can get as righteous as we’d like about “getting to know somebody’s soul” or the purity of meeting people without our hangups about looks, but without that physical component, it’s impossible to guarantee that you’re going to be attracted to somebody in person.