Based on my experience planning and buying millions of dollars in advertising for events, and seeing the results first hand, platform allocation—the share of dollars invested across various media platforms like newspaper, radio, TV, outdoor, digital, etc.—is the most important driver of campaign performance.

It defines who sees your messages and the size of the advertising package you deliver to them. If you get this wrong, no follow-on media buy variables (i.e. rates, placement, timing, etc.) will make much of a difference.

If you want the best results—as many attendees as possible—make sure your platform allocation syncs with the current media habits of your target audience.

Don’t over-focus on "getting the best deal." Yes, that is important, but it is secondary to platform allocation. Who cares that you got a great rate on an ad purchase if you are not efficiently reaching your target set with the right media mix?

Another error to watch out for is "shiny object syndrome”—chasing the newest, coolest media. It can kill your ROI through misallocation of dollars. You need to stay on top of the latest media, but don’t outrun your audience.

At the same time, if you are afraid to move out of your comfort zone and continue to invest in legacy media strategies that are now underperforming digital media, you will also hurt your ROI.

Platform allocation also affects your ability to achieve optimum reach and frequency. If you spend your dollars across too many platforms, your media buy will be spread too thin to achieve the necessary frequency to move the needle. On the other hand, if you concentrate your dollars too tightly, you will overspend on certain targets, while failing to reach other potential pools of attendees.

Finally, platform allocation can help you balance risk and reward in your media buys through diversification, especially beneficial as you spend more and more money in new digital media.