I'm pretty sure my grammar is off in that title, because I'm awkwardly writing around a missing word.
If a salesperson has time to call one of two customers, he or she will want to reach out to the one which, based on all the information available, is more likely to be interested in making a purchase. You could say "the stronger prospect". Is there a single-word adjective or simple phrase to represent a measure of this "likelihood-to-buy" quality in a prospect? "[Prospect] strength", "quality", and "score" come to mind, but they're vague, I'm hoping for something more specific to the world of sales. I'm not familiar with their jargon, I just learned what a "spiff" is the other day.
"Interest" is close, but the context is one of data mining based on factors other than the customers' expressed interest, so I think that would be a little deceptive.
For context, this will be a field in a customer relationship management app.