> For sites with big ticket items where the transaction doesn't take place online, it can be trickier to try and attribute the sale to a certain ad campaign.

How do they do it? One method I can think of is to show different phone numbers for users that have been cookied as coming in from different ads.

The company I currently work for does exactly this for car dealer websites. We have separate tracking numbers which display on car dealership websites depending on the source.

We actually found another vendor that does this on a per visitor basis (ie. each visitor gets their own tracking number). While I think THAT is overkill, the technology is there to do this kind of thing without too much overhead.

I believe you could do the same thing with a form and a simple bullet or dropdown that lets the potential client identify as education, business, etc. Once submitted, you could be taken to a different landing page based on the responses (bonus points for content relevant to their business).

The more sticky situation would be phone calls if you have a number.

Although using this method doesn't directly attach sales to conversions, it seems it would help qualify leads a little better and hopefully maximize you Adwords spending.

Think car dealership. The same general principle applies, but your data sources are dirtier, and the metrics are a bit different. You'd want to track things like cost per call, cost per physical visitor, etc. For effectiveness of online to call campaigns, you could use things like twilio or mongoosemetrics. Then, when sales happen, you could use phone numbers to trace back to the origin campaign.

For big ticket items you could count all the phone calls and contact form submits as conversions... but then calculate the final conversion rate manually as leads-to-purchases are tallied up.