The back-to-school season isn't just for kids. Now is the time for marketers to get a leg up against the competition and shake off the end-of-summer blues.

There was a bit of a chill in the air this morning as I departed for work. Autumn is right around the corner. Soon the kiddies will be heading back to school to focus on their studies and getting used to having homework again. As marketers, you might be well-served to do some homework of your own.

September is a great time to refocus on a few basics:

No. 1 -- Inventory for your ad campaigns
September is a great time to negotiate for ad inventory. Sales reps are doing their best to slide in some last-minute deals to make third-quarter numbers, particularly for remnant inventory that could be attractive to direct response marketers. They'll also be looking to kick off the fourth quarter with a bang as well.

Post-Labor Day, you'll find reps catching up after a long summer of meetings postponed due to vacations, Summer Fridays and a general inability to get all stakeholders in the same room at the same time. You'll see more requests for face-to-face meetings and emails touting inventory specials. If you have an opportunistic media budget set aside, September is a good time to be looking for proposals for how to allocate it. If you've had an advertising test sidelined, now might be a good time to resurrect it to take advantage of discounted ad inventory.

No. 2 -- Shifts in consumption habits
There isn't really a pronounced seasonality to digital media consumption. Certain categories will flatten out in digital during the summer, but the slack is taken up by other categories and new sites and applications. Come September, there are some shifts to be aware of, though, particularly among young people. For instance, you'll likely see a decrease in instant messaging usage with the under 18 crowd. They've been using it all summer to keep in touch, and they won't need it as much since they'll be seeing one another at school. It remains to be seen whether a similar effect will be seen in social networking, or whether the graying of social nets like Facebook will flatten that out.

Take a look at your digital campaigns and look to see whether or not any of the venues in which you're advertising might take a hit from shifting consumption habits. This tends to affect direct response advertisers who depend on a steady flow of remnant inventory to keep CPC and CPA campaigns running smoothly. If you're getting sales flow from instant messaging channels or social networks, you might want to have some backup plans in the on-deck circle in case remnant inventory starts to dry up.

No. 3 -- Shifts in the behavior of other advertisers
Back to school kicks off a series of events that comprise the retail season. (As far as the offline retail environment is concerned, it's already October. Have you seen the Halloween decorations in the stores this past week?)

You may notice competitors beefing up their presence in digital leading into the fourth quarter. September is a good time to actually take those meetings with reps and ask about what competitors are doing. What kind of inventory are they interested in? Have they made inquiries about sponsorships or category exclusivity? Are they doing holiday promotions?

If you do some homework now, you'll be better able to show the folks further up the command chain what the competition is considering. It might help shake loose some additional digital budget dollars.

And you thought back to school time was just for the kiddies…

Tom Hespos is the president of Underscore Marketing and blogs at Hespos.com.