An advantage you have is people who are already invested in your site. If they have a good ranking going or some friends on the site they won't be very interested in packing up and going elsewhere. You could try and make the site as viral as possible (wall integration, send to a friend, etc) to try and snowball your users into more users.
Not going to say I use them all the time but I sure do love me a good table. Just today I had to debug some code that was a css-simulated-table that went all wonky with its floats and clears.
I more or less did this... couple semesters into a CS degree I did a 180 and got into my colleges art program. While I had a blast I still don't think it left me in a position where I could get a gig as a full time UI/Graphic Design guy. Like anything else, you get out what you put in and I spent too much time coding outside of class to ever get real good at the design. Still happy I did it though because I am at least able to scrap something together when I need to.
TL/DR: Studying something in college != being a pro at it
Once a month or so during college I'd devote a day to taking an ADD medication and working all day. I feel that I did more, and better, work under the influence.
I would start working on a Sunday morning at 8AM and besides a lunch break I wouldn't take stop until 10PM or so. I was working on an art major as well as doing some web development on the side at the time, and for these sessions I feel I was working at or above my normal creative and intellectual output for the majority of the time.
Besides a stamina boost for the day I also feel there is a similar effect to the Balmer Peak. (http://xkcd.com/323/) I would be much more confident then my average self, and because of it try (and sometimes accomplish) things that I would normally shrug off as out of my league.
Just got the opinion of a real live 21 year old woman on this topic. She uses Facebook on a daily basis and is tech savvy enough to use Gmail filters intelligently and download torrents.
Here is the rundown of what she said:
-Doesn't read online news/blogs
-Clicked 5 or so Facebook adds lifetime
-Watches a copious amount of online TV (Hulu etc.)
-When looking for new services online she googles what she is looking for (budget manager, etc.)
If I was going to go about a marketing plan based just on this anecdotal evidence I'd say SEO is quite important, and perhaps getting some adds during online videos (how expensive is this?) would be good because she seemed very adverse to clicking on anything she didn't go looking for in the first place.