That’s a good question. It’s supposed to simply define how many people have appreciated your comments and questions, but that measure can be misleading, especially if there is people you know on the site or people on the site who want to give you more lurve than you deserve simply because they like you, not necessarily your answer.
So, it’s not a real indicator of whether your answers and questions are popular, but unfortunately, could be more about whether you’ve developed relationships with others and are given lurve because you made any answer. Also, as discussed in other threads, sometimes people like to award a user lurve just because they answered a question (ie like the person asking a question and hoping for participation).
So I say, take lurve with a grain of salt!