In my 2 months of the beautiful Steemit journey, no Steemian has commented on my posts without receiving a suitable reply. Comments from bots like 
There's a sense of human connection when someone takes out time to comment on my posts. I really appreciate that effort and find a way to reward that effort.
If it's just a comment, I will certainly reply to it. But if it is a wonderfully crafted comment which adds value to the discussion in the post, I must upvote it with 100 % power.
I think it is important to reward efforts of others. Think of it in your own terms. When you create a good post, don't you want to get rewarded through good upvotes? In my opinion, well crafted comments take both reading and writing. Therefore, they must be rewarded.
It is my normal practice that I upvote good comments wherever I find them; on anyone's post. However, it is easiest for me to have access to the comments on my posts. That's why I reply to each comment and look for the most valuable to give my upvote as well.
It may be a small contribution from my side to the author of comments but I love the interaction and wish to reward it. Minding the fact that I regularly used to get more than a hundred comments on my posts, replying to every comment becomes hectic.
But I still do it because it matters to me.
If you leave a comment, you will get a reply. If the comment is valuable, you'll get an upvote too. That's my way of encouraging the most important part of Steemit community; the interaction.
