As I buy media for my clients, I hear hundreds of sales pitches annually, especially for digital media. While I have heard some great ones, I am amazed at what I hear—and what I don't hear—many other times. 
 
Selling digital media is much different than selling booth space, exhibit guide ads and trade pub ads. Make sure the people who sell your digital media products understand them, have engaged with them and can clearly communicate the different value propositions. They should also know the specs, features, terminology and metrics for all of the online ad products they are selling.
 
Also, many sales reps want to bundle ad products. I am a big proponent of cross-media buys. However, let’s say a sales rep suggests that I buy a package for one of my clients, for example, a trade pub ad and online display ad campaign, because it will enable my client to more effectively reach their audience. If I ask what the audience duplication factor is between the two ad products, and the sales rep does not know, how much confidence do you think I will place in this recommendation? 

It is always clear to me when a sales rep is just reading off a rate card and does not fully understand what he or she is selling. These experiences don't instil confidence in the buyer (in fact, they also don't instil confidence in the sales rep) and can cost you revenue. 
 
You may have strong online ad products but lack of training of your sales reps may cause a potential advertiser to not recognize the value, and thus result in lost dollars.