Essentially, this quote is pointing out the merits of being a good listener. For instance, if one is constantly listening to others, they become popular as a friend or comrade simply because they are willing to hear what another person has to say.
In addition, by constantly listening to others, one may gain the knowledge of others' experience. For instance, every person has had different life story, and by listening to those of others, we are able to learn from their individual accounts. Being a good listener definitely has its advantages, and this quote is attempting to elucidate two of them.
This quote is basically saying that there are two benefits to being a good listener. The first benefit is that you will be popular everywhere. This is because people like to talk. Someone who is a good listener will be popular because they are giving others the chance to be the ones talking. Everyone likes a good listener. In addition, a person who is listening more than they are talking will learn something. Listen long enough and you will eventually hear something worth knowing.