I am running a ppc campaign in my site http://www.siennagroup.com/ and would like to know when a conversion takes place. I do not sell anything online. How can i detect if i have got a lead from this campaign?

For most clients who dont have online sales I recommend a completed contact form page or a view demo page. It really depends on what the desired action you want each visitor to take is.

Thanks Jeff
I think a "Request for Quote" page should be added to the site.