End user security awareness training, when done often, is a huge benefit, but only when it changes the culture of the company to be more security minded. Training insiders helps eliminate mistakes that could lead to a breach, as well as helps them notice odd behavior by malicious insiders or fraudsters.
Perimeter CTO Kevin Prince has kindly offered up several tips for preventing a data breach. Kevin says, "Being aware is always the first step. Taking a layered security approach and looking for the policies, procedures, and solutions that can best mitigate security threats is best."