Think what you will about the value that social network advertising can bring in terms of Web traffic or out and out sales, what is interesting is not the demographic targeting that is available through these outlets, but rather the incredible amount of keyword data that is ripe for the picking.

I reintroduced myself to Facebook Lexicon today, a tool to count occurrences of words and phrases on Facebook users' walls over time. What does this have to do with keyword seasonality and advertising you are undoubtedly asking? Well, if you know when certain terms are used, you can pretty much guarantee that that consumers will be searching for various solutions to their problem. And if we know when users are searching for those terms, we can leverage that knowledge to make informed media buying decisions about when to place ads.

Let's take a look at the key phrase "the flu". You can see in the graph below that starting around the first of the year all the way through early April, Facebook users are posting those words on others wall - for example, "I have the flu." So how do you leverage that for your own benefit? Advertise to the Facebook audience around these times specifically. You could even further your targeting and leverage other public information such as the Center for Disease Control and Prevention's Flu Activity and Surveillance reports. Using that CDC information, we know which regions are being hit the hardest by the flu from week to week and can geographically target states with our flu remedy.

Now you might be thinking that understanding the seasonality of keywords is excellent information to have and all, but what if you really wanted to dig deep into these keyword trends - what other information is available. How about the day of the week that these terms are used? And what if we could cross-reference one term with another to determine a relationship between the two. How about the keywords "party tonight" and "hangover" - that should give us some valuable insights. Someone could extrapolate several interesting things from a graph like the one below in relation to the aforementioned keywords. For example, you can see that the keyword "party tonight" starts to increase on Thursday and peaks on Friday and Saturdays. What we can also see is that the peak of mentions of the keyword "hangover" follow very closely and appear the next day.

While both "the flu" and "party tonight" vs. "hangover" are rather obvious examples, it's clear that Facebook Lexicon is a powerful free tool to help you get inside the minds of social media users.