One clear advantage online ads have over their television equivalents is inherent targetability—the relative ease with which advertisers can use them to reach niche audiences with customized messages.

In fact, ad buyers have so many targeting options in the modern marketplace that many consultants and staffers get to feeling a bit overwhelmed by the wealth of choices. Technology Bytes is offering a helping hand this issue by breaking down some of the basics when it comes to your online ad targeting options.

Geographic: Geo-targeting is a no-brainer for most campaigns, since it rarely makes sense to waste money advertising to people who can’t vote for your candidate. Google, Facebook and most ad networks allow advertisers to restrict their buys by state, metropolitan area or by a range of zip codes. Some, such as AOL’s Advertising.com, can target by congressional district.

Also, think mobile: candidates have used geo-targeted search ads to try to catch people using their phones to find their polling places. And GOP presidential hopeful Michele Bachmann used mobile ads to hit Minnesota State Fairgoers in 2010. Geo-targeting isn’t always exact, particularly considering the snake-like lines of gerrymandered districts, but it’s a good way to preserve resources and deliver messages to residents of a defined area.

Interest: Next up is interest-based targeting. Here we’re talking about delivering ads to people based on what they care about, either long-term or at a given moment. Google Ads and other keyword-related search ads fit into this category, since they advertise to people based on what they’re looking for at the time. Most ads on blogs and issue-focused websites are also examples of interest-based targeting. Campaigns can use them to reach political activists and donors in a given state or region who care about a particular subject. Geography can matter less in interest-based targeting, since a campaign may actually want to reach donors outside its state or district to build a broader fundraising base.

Demographic: With demographic targeting, we’re starting to get personal. Does your campaign need to reach women between the ages of 45 and 60 in Texas? To achieve that, you’ll need to work with someone who knows who they are. Sites like Yahoo, AOL and Facebook gather plenty of data on their users when they sign up and as they interact with content, giving advertisers the ability to reach precise slices of their audiences. Targeting left-handed pipefitters with a taste for pro wrestling may be a bit much to ask, but many ad networks can come close.

Note that interest and demographic targeting often overlap. For instance, when we talk about niches like the “mommy blogosphere,” or parenting-focused blogs that reach an overwhelmingly female audience in their twenties, thirties and forties, we’re essentially doing both. Also, audio and video streaming sites like Pandora and Hulu offer advertising channels like Spanish-language programming that functionally target interests and demographics at the same time. Finally, companies like Resonate Networks combine analyses of what individual content audiences care about and their demographic characteristics to help clients determine what messages will work best with which niche communities.

Individual: Now we’re getting a little creepy. Ever gone to a company’s website and then seem to see their ads wherever you look online? Congratulations, you’ve been targeted, likely using a digital “cookie” that a website placed on your computer. Using cookie-based targeting, cross-referenced with voter files by a company like CampaignGrid, campaigns can reach all identified Democratic or Republican voters in a given district. Combine those lists with consumer-information databases, and campaigns can get really specific about which messages they deliver to whom.

Choosing the Tools: Finally, the million-dollar question: which targeting options should a particular campaign rely on? Therein lies the consulting magic.

Colin Delany is founder and editor of the award-winning Epolitics.com. A contributor to Campaigns & Elections, Delany writes C&E's Technology Bytes section. Send him a pitch at cpd@epolitics.com.

Also in Technology Bytes this issue: social media monitoring for the masses.