Edit: For example - http://techcrunch.com/2011/08/29/anti-web-analytics/
But if you are only using Compete you are doing it all wrong.
Think of Compete, Alexa, Quantcast, Similarweb (A newer site with some very cool data http://www.similarweb.com/website/ycombinator.com), Adbeat.com (For display intelligence), NerdyData.com (Which is really good at letting you search for tracking tags that marketers use) and the dozens of other sites and services currently available on the market etc as different color paints on a canvas.
Trying to create a photorealistic painting (accurate picture of what's working for your competitors) with just one color will yield poor results. Like the author in the post does, you need to combine and mix them for the the best outcome.
Additionally, Michelangelo can use the same paint that you and I have access to, and end up with the Sistine Chapel ceiling. While I'd be proud to just be able to end up with a ceiling that's an even shade of whatever color I chose. A skilled marketer masters and understands the nuances of these tools and use them to work magic (At least in the eyes of someone without this knowledge).
In the past, I use to jump from site to site collect data, but now when I need to research a site or market, I'll use the Follow browser extension http://www.follow.net since it aggregates all the information into one place. It's not perfect because I still have to collect data from other research sites, but only when when I see it's worth digging deeper.
In my 13+ years of marketing online, I can say without a doubt that if you can figure out how your top 3-5 competitors are marketing online and how effective their marketing is, you can almost always out market them or at the very least have the data you need to be very competitive.
Disclaimer: I'm good friends with both founders of Follow.net and Adbeat.com I did quite a bit of product dev work with the Follow team early on and have done customer acquisition for both companies.
It's especially annoying when people whose opinion of your site matters quotes Compete numbers and trends for your site to you as though they mean something.
There was a really good post that I can't find where Spolsky (I think) was writing incredulously about how Compete was telling him that Stack Overflow traffic had fallen over the past 6 months or so, when it was the opposite, to an extreme.
Seriously, worse than useless.
Your best content is always going to be on topics that exist on the customer's pathway from the discovery of a need or problem to the selection of a solution. That type of content will almost always win out over what is popular.
Example: "Differences between Contractor and Employees" -> "Salary for X position" -> "Payroll Taxes" -> "Payroll Software" -> Conversion to Customer of a Payroll Software Company
Figures she already is a founder...