Researching sales techniques -- can anyone recommend...

[wakemewhenitsover]

...a great website or an article online?

My nephew, fresh out of college, just got his first sales job, working on commission, and he has to be a closer on sizable purchases. He told me his clients, especially women, tend to balk when it comes to finalizing the sale. He asked me for some advice; in other words, how to get a jittery customer who may be a lookie-loo, or just flirting with the idea of buying, to commit to a purchase. I've never worked in sales myself, but I assumed I could find some great advice for him on the net. So far, everything I google leads to some cheesy sales technique tape that I can purchase. That's why I've turned to DU. Thanks in advance!