arieng - 7:28 pm on Feb 22, 2010 (gmt 0)
If you're using PPC to drive offline conversions, tracking their efficacy can be pretty difficult but not impossible. Here are two things that might help, but both are fairly complicated.
Disclaimer: I have not implemented either of these strategies. I'm working within a more traditional e-commerce model with easily trackable conversions. However, I have studied both of these techniques and I'm sure there are many here that can speak about them more knowledgeably.
1. Session tracking - As PPC_newbie mentioned, using an online form is one way to track sessions that you can tie back to the referring source. However, it is possible to similarly track email and phone responders. If you have a "Click here to email" link on your site, you might try coding the link to fill the subject line or email address with a unique code that you can track back to that session, which you can in turn tie to a referring source. Phone calls are a little more difficult, you usually have to place something like "Refer to code ######" next to the phone number, though even then most users won't remember to use the code. Have whoever is answering the call request that code specifically, and maybe even offer the user a financial incentive or freebie for using the code.
2. Attribution - Most analytics programs use what's called a 'last-touched' attribution model. That means when a conversion occurs, the most recent referring source gets credit. So if a visitor clicks on an google ad, then clicks on a banner ad, and then bing's you and clicks on the organic listing before finally converting, Bing organic gets 100% of the credit for the conversion. Some analytics solutions allow you to divvy up this credit, either equally between all sources in a given time period, or by some more complicated attribution calculation.
Not sure if either of these will help, but there are solutions out there for business models like yours. They may be expensive and they may be complicated, but they do exist.