You started out with friendly, so now you're approachable. Then you worked on being relevant, so now you're interesting to them. To strengthen the bond, you now need empathy.
Empathy is that too-often elusive feeling of understanding where someone is coming from. It's not too hard since we're all human, we need appreciation, security, etc. But it's hard because ... well, we're human. It's hard work to keep your mind clear on other people's needs when ours seem so pressing.
On the other hand, sometimes it's very nice to focus on their concerns and let yours go away for a while. If we can think of empathy as a gift to ourselves like that, maybe we'll get better at it. And that makes us much more likeable. How can someone not appreciate you when you really seem to "get" them?