A "tip jar" is merely a comment that you make in your own diary, right after you post it, with the title "Tip Jar" (or some creative version thereof).
Kossters prefer that you make one, as mentioned in the FAQ.
Follow me below the fold for some reasons why!
The first reason is mojo. By rating your comments, not only can other users express their pleasure (or in extreme cases, displeasure) with your diary. It also becomes a way to quickly see how popular it is with other users.
To "leave a tip," hit that radio button at the bottom of the comment, right after the "Reply to This" link, that says "Recommend."
Also, by posting such a comment, it indicates to people that you intend to stick around and watch for responses to your diary, and maybe interact with other people who are drawn to comment in it. Because this site likes to build community, people like it when you stick around to interact with them. After all, you've asked people to read your thoughts-- why not do your part to read their responses?
Over time, your style will develop, as will friendships based on common interests or blogging experiences. To think that it all started with a tip jar!
I've been at this for... it'll be a year this summer. So, I'm no longer a "newbie," but nor am I an old-timer.
I am posting this because I see a lot of diaries going up tonight without tip jars, so I want to do my bit to help bring others up to speed on the norms of diarying here, as others did for me. I also want to invite older-timers to jump in, with additions or corrections to my content, and any funny stories they might be able to tell about tip jars, mojo, and interacting with your diary audience!
Thanks for reading! I should be around (if occasionally distracted) for a while, if ya wanna interact below.
Revision #1: Added par. telling "how to tip."