Monitoring the competition is important if you want to learn how to beat them.  Whether you watch your competitors or not, they're most likely watching you.  But when your business is online, it's not always clear how to gather information on the competition.  A post at Search Engine Roundtable post talks about a discussion currently going on at the Search Engine Watch forums about how this online competition monitoring is to be done.

As pointed out at SERoundtable, a look at your competitions server logs is probably the best way to find the information that you're looking for.  But that's not normally possible.  Instead, the folks having the discussion have mentioned a few online tools that might help, including:  the inaccurate Alexa, Quantcast, and Compete.

Doesn't sound like much, huh?  Luckily, those three options are far from a complete list.  Fortunately, SERoundtable has posted a link to another list of online services at the SEOmoz Blog that's far more complete.  With dozens of links to dozens of tools, this is a pretty complete list of ways to find out what's going on behind the front page of your competition's website.  I'd highly recommend giving it a look.