Most of our clients are B2B, so they have lead generation websites.  Our goal is to drive qualified traffic to their sites from search engines, and encourage those visitors to "convert" -- fill out a contact form, register for a webinar, request a white paper, subscribe to a newsletter, etc.  At that point, the lead goes to the sales team and our job is finished.

At least, that's how it used to work.  We've always reported to our clients each month on the number of leads we've generated for them.  That used to be enough.  But now that we're in a recession, companies that are spending money on search marketing want to know how many of those leads are closing, how much revenue they're generating, and what the true ROI is.  Fair enough!

We're currently working on some technology solutions to "bridge the gap" between a visitor's data in web analytics (when they turn into a lead), and the same visitor's data in Salesforce or other CRM databases (when they turn from a lead to a sale).  So this is an exciting development.

In the meantime, I came across a good article on this topic.  It recommends scoring leads and judging search marketing results by the quality of the leads more than the quantity of the leads.  Here's "How to Optimize When You Have Long Sales Cycles."