Do you think it would be possible for us as a community to scrounge up 5000 Bitcoins for a frontpage ad on the Wall Street Journal?
Possible? Yes. Worthwhile? Not yet.
An effective ad does two things. First, it gets the viewer's attention. Second, it calls the viewer to action. It says, "Here's something super cool. Now go out and buy it!" The call to action has to be something ultra simple. It's usually either to call a phone number or go to a web site. Once the user takes the action, that's where marketing transitions into sales. If we're talking about a sales phone line, a salesman needs to answer that call and secure the sale. If it's a web site, the site itself needs to do the selling to get that user to take the next step (e.g. download a program, sign-up for a service, buy a product).
Marketing is like chum. You're throwing bait in the water to attract fish. Sales is what you need to do once the fish are circling to set the hook and reel them onto the boat.
Right now, we have nothing on the sales side. The average consumer will never, ever be able to figure out the Bitcoin client. A super simple web-based wallet service designed for non-technical users needs to come before expensive advertising.
The Get Firefox campaign may provide some good examples for us to imitate. Remember Firefox started out as Mozilla and it wasn't nearly as user-friendly ("dumbed down") as Firefox's current incarnations. Once they had their sales strategy in place, that's when they did their full page ad in the New York Times (
http://www.mozilla.org/images/nyt_ad_2004.png).