You're a stakeholder in a company, DMO, or other organization and you need some marketing done. Where do you turn? The old way to do it is to go out and hire an Advertising Agency. I'm still under 30 and I've quickly realized that there is no such thing as a good, all-around ad agency. I managed to learn advertising and ROI tracking on my own, through experience, and I'm honestly ready to teach anyone who shows me a reasonable effort to learn.
Their interests aren't aligned with yours
What do they do? Simply put, they do some shopping and take a cut off the top. Economically speaking, they are rewarded for doing as little as possible while convincing you to spend as much money as possible. I know it sounds cynical (it is), but any successful business person is far better off hiring an agency for the learning experience, then cutting them loose and doing it yourself. You know who your customers are. You now know how to reach them. Advertising takes a lot of tailoring, and constant monitoring. You WILL NOT find an agency on the face of this planet who is willing to do that for you, no matter how much you pay, and ESPECIALLY if you have a strong sense of urgency.
What makes me qualified to say all this? I oversee an annual advertising & marketing budget of about $300k. From that, I purchase print (collateral and ads), internet PPC, graphics when needed, and production. In the past 10 years or so, I've adjusted that budget from about 20% internet advertising, to 80%. I did this after obsessing over ROI metrics, and realizing that traditional (print, TV, etc.) advertising is a very imprecise form of advertising. Facebook and internet re-marketing are the golden standard because of their depth of targeting parameters, but re-marketing is at least 300% more expensive than Facebook. Google is great for a very specific application, but still less precise than Facebook.
Another frustration that I'll go ahead and vent is my on-again, off-again experience with the South Padre Island CVB, my hometown's DMO. All I'm willing to say that this time is that their current agency delivers very low competency and a very high price. They have an advertising budget of over $2 million, which they spend all of, with shit to show for it.