Getting people to look at your work
The best way to meet people and get attention on The Duck is to post (reasonably) in the forums and on other peoples' comics. The Duck is as much about social networking as comic hosting, so being an interesting, nice, helpful person will get you friends and fans.
There's also a really useful (and long) forum thread all about how to get people to check our your stuff, with lots of great advice. How do you make people read your comics?
Most of the advice you read will involve these ideas:
Be interested/involved with other people and projects
Engage with your fans (like replying to comments, having a comic forum, etc.)
Offer a good 'product'
Develop an update schedule you can stick to
Try not to take too many hiatuses or rely too much on fan art/fillers
It's OK to promote yourself, just don't get all spammy about it
The most important thing to know is that having an awesome comic but posting it up without ever talking to anybody or promoting it isn't going to get you anywhere. How will people ever read your comic if they don't know it's there, or who you are?
The Duck is also a good place to receive more serious criticism regarding your work, for those more advanced creators who are looking to improve. Although not everyone will offer unsolicited critiques, there are occasional projects set up around reviewing comics. You can also make it known on your comic page that you welcome criticism.