This is the question posed over in the Digital Marketing group on LinkedIn (you should check it out) right now. People have pointed out the need for involving more than just sales and marketing in recruiting new customers, which I think is an excellent point. 37Signals is a great example of this, where the founders are actively involved with their user community.
There has also been quite a good discussion about the sales funnel needing to become more a “funnel of interest,” with a push towards multiple opportunities to boost interest levels. This ties in with some thinking I’ve been doing around SaaS companies and trials as a sales/marketing tool. Not enough SaaS companies use trials as well as they could. Lots of times, user trials are completely unguided, which works really well for advanced/expert users. But you run the risk of losing a lot of potentially solid leads because they, perhaps, become overwhelmed by “Microsoft Office syndrome,” the trial can be seen as too complex.
Finally, a recommended read: 7 Marketing 3.0 Lessons from Inbound 2012.