I just reviewed Marketo's recently released Definitive Guide to Lead Nurturing. Don't let the vendor logo fool you, this is a document that is a must read for all demand generation professionals. It's filled with useful information, starting with the basics and then working to the advanced.
Excerpt: "the process of building relationships with qualified prospects regardless of their timing to buy, with the goal of arming their business when they are ready. Building a relationship with a prospect is the same as with any long-term relationship — you can’t force someone to commit (to a purchase, in this case) — but you also cannot afford to lose individuals because their willingness to buy doesn’t match your readiness to sell."
The document is full of examples, includes several useful tools as a take away, and also is full of soundbites from industry leaders such as Tony Jaros of SiriusDecisions, Ian Michiels of Aberdeen, Marketing Sherpa, Scott Albro from Tippit, and more.
What I found most useful were the examples of calculating the ROI of Lead Nurturing. Specifically the section of the impact on opportunities won.
It's a must read. Go download it now: Definitive Guide to Lead Nurturing