If your marketing team is doing its job, it will get more coverage. Web crawlers are the perfect tools for comparing the effectiveness of marketing. If you’re spending any money in AdWords, you should understand which ads are being taken, how much they’re worth, and how you compare in terms of ad-spend against your competitors. Some of this information is available through competitive analysis sites like Spyfu (Figure 16-10).

Google Trends is another good resource for comparing competing products or services, and it will show you which news stories occurred in concert with changes in a particular trend line (Figure 16-11).

Figure 16-10. Spyfu.com provides a detailed analysis of ad-spend by company or by keywords

Figure 16-11. Google Trends, part of Google Labs, compares web traffic for specific terms

Don’t overlook competitive questions when designing your VOC surveys. Ask respondents which other products they considered or ask them to describe how they feel about you and your competitors.

Finally, here’s a dirty trick that exploits an information leak in CSS to let you test whether your visitors have also visited competitors. First, include links to your competitors’ sites on one of your web pages in an iframe the visitors can’t see, but that their browser’s JavaScript can parse. When visitors arrive, these links will be marked as visited or unvisited in their browsers (but they won’t see this). Then use JavaScript—which can see the links—to check the state of those links and determine whether they’ve been visited. (See http://www.azarask.in/blog/post/socialhistoryjs/ for more details on this approach.)

By sending this data back to your analytics platform, you can track how many of your visitors also frequented your competitors’ sites. You need to decide whether this information is worth the potential backlash you’ll face if you’re caught collecting data from visitors without their consent. It may be simpler—and more ethical—just to ask them.