For sales success to mean anything, we have to be given the opportunity to fail. The more we have the opportunity to fail, the more lucrative winning at sales can be. Celebrate sales failure. Embrace it. Commit to failing, because you can only succeed in a sales career if you also have the ability to fail.
The clerk at the neighborhood convenience store fail in the sales arena because customers come in and buy candy and beef jerky and toilet paper and ice regardless of what the clerk does. The clerk has little impact on whether the shopper will or won't buy, or will or won't buy more. [Not that these employees couldn't have an impact - they could. But this is not the modus operandi of convenience stores I've been in.]
But a real estate agent, kitchen designer, or door-to-door salesperson truly leaves a fingerprint on the results of the sales interaction. Failure (or at least mediocrity) is common in these disciplines, so the successes are all the more important. Here, the salesperson really helps to determine the outcome of the interaction.
Sales training won't help the convenience store employee much, or the discount clothing retailer or the grocery store employee. But it can help those who have the possibility of failure avoid failure by helping the salesperson to embrace failure, and in the process of doing so, embrace sales success.
Managers: design a system in which your salespeople can fail. If you do, success will be more likely.