I seldom reply also. But I will usually rep that person back. Sometimes I will rep a new member just to make them feel welcome.
I also use the "Friends" option. If I like the way a person posts, I will put them on my Friends List. Most of the people on my Friends List are people I asked, a few of them sent the friendship request to me first. It doesn't mean anything to me if they turn down my friendship requests, thats just the way things go. There are a lot of people out there I wish were on there, I just haven't got around to ask them.
We also have a "Groups" list. You can join that and let people know what you do. You can also post pictures there. These are all options that Cheryl has added to this site to make it a little more interesting.