CoPress

What a great question, you've hit home on a particular passion of mine, so get ready for a rather long winded answer. I'll try to keep my crazier ideas at the end.

@BradArendt, you've hit 2/3 ways to pay for online ads: by impression and by month. The last, is by click. Of course, there are hybrids of all three models, which the top ad networks utilize (Facebook, Google). The issue, is that all of these models have some inherit flaw. CPM doesn't reward for the effectiveness of an ad, Cost per click doesn't has the same problem and doesn't necessarily reward high traffic, and charging for a time period has the same issues.

Now, take into account that college media has a monopoly over the vast majority of the 18-24 year-old US population. That demographic should sound familiar to you as the most sought after by advertisers. Oh, and if my rough, non-scientific, survey is to be believed, less that one third of online college readership is actually students, it's parents and alumni, who represent a middle-class, educated, demographic – precisely what any good advertiser wants.

Translation: you're serving ads to a very valuable audience. And, you've got a monopoly on your niche market.

If these analytics are somewhat close to your internal numbers, than you're receiving roughly 3,500 pageviews/month on your site, which means that an advertiser can pay $20 to have access to your market for the whole month, and paying only $0.005 (half a cent) for each view of their ad.

If you ask me, that's far too little, and not enough to support your organization. In recognition of the bad economy, I'd only double to $10 CPM, and plan to increase quality web content in part to justify the increase, and to prepare for a larger raise in the coming years.

Geography

Now, remember those awesome demographics that we talked about earlier? They do have a huge downside: they’re usually not geographically similar. That means that you’re local adverts may not be your best market for online ads.

Take a look at your analytics, and I’m sure you’ll find that your pageviews mostly aren’t local. Try to serve ads that target all your audiences. Yes, an ad for a local pizza joint is good, but irrelevant if you don’t live near campus. Ads for Macy’s on the other hand, apply to everyone. Not to mention, national ads pay well.

In the same vein, don’t forget that you’ll have a lot of alumni visiting the site. Go to your alumni office. Tell them that. They may not know.

Alumni offices spend ridiculous amounts of money trying to contact alumni to get more money out of them. You can get a chunk of that money too! Make your case, and sell them a decent spot for a long-term contract. Then charge them a hefty amount  – after-all, you’re a great way of reaching their market. 

Concerned about relevancy for students? Go to the career center, and have them team up with alumni office. There’s gotta be alumni who want to hire interns and grads. 

Crazy? I was Crazy Once!

That said, let me present some crazier, more involved ideas.

@BradArendt points out, there's a lot to be said for type inventory you have. One suggestion of Revenue Two Point Zero, was to limit your inventory, therefore decreasing supply. This will allow you to drive up costs. Another, was to sell only larger, more eye catching ads, this should help to avoid ad blindness which is a huge problem for online adverts.

You might consider changing your inventory with those thoughts in mind.

Currently, the Hullabaloo has 3 display ads on the site, one of which was Google AdWords. I'm sure you know that Google Ads, while convenient, don't have great revenue, and you'll make much more money from selling ads yourselves.

Of course, that means having a motivated and trained online ad sales team. Who, since they're paid on commission, don't stand to gain much by selling online ads. Increase the cost of online ads, and you actually stand to sell more.

…They Put Me in a Little White Room.

OK, with me so far? Now let's get out-of-the-box:

Institute a rule that 60% of your ads must be either a coupon, or a notification of a sale/deal (that's actually legit), with the intention of increasing this to 95%+ in the coming years. I base this off two facts: people describe online ads as annoying, and in my own observation, print ads, which are usually described as informative, are primarily coupons or notifications of sales.

Of course, coupons are really the way to go. They will not only make your users happier, but they’ll drive traffic to your site and to your advertiser’s site and store. It’s a win all around.

Now, how do you serve them? Offer some sort of hybrid: charge for a run time, but make a deal with your advertiser that if you get a spike in traffic, they’ll be charged for the additional views. It’s your market, control it. This clause will allow you to ensure that when high traffic comes, you’re not out of inventory.

But… don’t be evil, if you’re advert wants to opt-out of the deal, then let them. With no hassle. Just be sure to sell enough ads to have an inventory ready if you do spike.

Take all this as you will, I recognize I've gone beyond the scope of your question, so take from this what you will, but please do take my basic message to heart: your ad rates can be much higher. Don't be afraid to charge for what you're worth!