Surveys are one good way to estimate this multiplier. Printable web-to-store pdf POS-scannable coupons are even better.

Here’s a post on the web multiplier idea:

http://www.rimmkaufman.com/rkgblog/2006/12/18/your-off-web-revenue-multiplier/

Had I been writing this a year ago, I’d have included “call center spillover” in my list of search-leading-to-untracked sales. But some catalogers are starting to embed source codes on their web pages and ask for these codes in the call center.

Post on that inexpensive incredibly powerful idea here:

http://www.rimmkaufman.com/rkgblog/2006/11/09/can-you-read-me-the-code-on-the-bottom-right-of-the-web-page/

but my guidance to CMOs starting out would be: Be consistent.

A lot of the firms I talk to place an “incremental sales” burden on the direct mail channel. If they’re going to start measuring the impact of search, it should have to live up to the same criteria that other channels are subjected to.

There has been some excellent work in attempting to allocate brand communication ROI. I love the stuff done by Don E. Schultz, for instance. In a spreadsheet that takes in all brand communication expenditures, you make WAGs (wild ass guesses) as to the proportion that something contributed to sales in that fiscal year. These metric can help assign some guesses to the support of search in the “real world” — even if the guesses prove to be off somewhat.

Ya gotta start somewhere!

One other point: Even for those that aren’t using it for navigation, their intentions are not the same. There’s a spectrum of intention from exploratory to validation.

Some consumers are truly exploring, i.e., have not made up their minds about the specific product and provider they will ultimately choose, and attributing a sale (again, online or offline) is valid.

But many consumers are validators. According to data from Yahoo! and Compete, nearly eight of ten credit-card related searches are “brand-specific” — that is, somebody typed in the name of the brand vs. product-related terms. Regarding online credit card activity, Forrester found that 34% of consumer said the Web helped them “confirm the choice of product and provider they had already made” or “choose the right product from a provider I had already selected”. In contrast, just 9% said it helped them find a product from a firm they hadn’t already considered.

Should this stop firms from purchasing keywords? No. But they need to be more cautious about assigning credit to the sale to the search engine.