Well, we tend to use the terms "proactive" and "reactive" together in my company's sales and marketing. In our usage, "reactive" sales would be waiting for the client to come to us, or taking a passive stance. "Proactive" sales would be identifying the most likely clients/customers ourselves, and then getting out and selling to those customers.
Considering that sales are generally quite competitive, with several different versions of a similar product available to any client/customer, the "proactive" approach is the only one that makes much sense (unless you either have a complete monopoly, or an incredibly strong reputation and brand image) outside of a retail setting. You can't afford to sit around waiting for the clients to come to you; you have to not only get out there, but you have to convince them to buy your product instead of any competitor's product.
This, in turn, means anticipating their questions and their needs, and being prepared. Again, the "reactive" salesperson waits until a question is asked, then tries to find the answer; or waits until they find out what the client's needs are, and then tries to find a way to tailor their pitch to that need. The "proactive" salesperson has already anticipated their questions, and answers them before they are asked; and tailors each presentation in advance to the specific customer's anticipated needs.
Proactive sales pitch: appeals to the client/customer's needs directly, and answers most/all of the questions they will have. Remainder of discussion focuses more on finalizing the sale, rather than on explaining the product and answering questions. For example, the computer salesman who goes to a large company and tries to convince them to buy 100 new computers.
Reactive sales pitch: a generally generic pitch that covers the basic facts, and then is modified based on the client's feedback and responses during the presentation. Presentation is (hopefully) shorter, but much more time is spent in expanding on and explaining points not clarified in the original presentation, rather than on actually closing the sale. For example, the computer salesman who works in a computer store and sells individual units to walk-in customers for whom he has no background knowledge.
Others will have other meanings/interpretations for these terms, but for our purposes, this works quite well. And while I will admit that the words "proactive" and "reactive" get rather over-used in our company, they are also absolutely essential concepts. Chinese sales staff tend to be very, very reactive (a legacy of the previous state-owned enterprise system in China), so it is necessary to stress the difference, and push for a more proactive approach to sales and marketing.
The sad thing is, the idiot who thought that button was a good idea probably makes a lot more money than I do. I really felt like Home Depot corporate was insulting my intelligence. 
