I saw this topic at a startup conference: "Sales for Start-ups How to Market Like a Rock Star!" If you ever see that topic, RUN!
Sales is NOT Marketing. They are different.
Laura Lake explains, "Marketing is everything that you do to reach and persuade prospects. The sales process is everything that you do to close the sale and get a signed agreement or contract." I would say that Marketing is every touch of the prospect and client - from your ads, your website, the way you answer the phone, what your service techs look like, how your sales people approach the prospect, how you handle every contact with your marketplace - every contact and impression with your prospects and customers goes into how your brand is perceived; thus, it is marketing. Sales is the point at which the prospect approached the company or the salesperson approached the prospect. Thus begins the sales process. Thus begins the Funnel. (An interesting look at the Sales Funnel here from BNET.) As he says, Marketing helps fill the funnel, sales get's them to ink a contract.
As I have been discussing since Austin, even in Marketing, there are different activities. Branding and Lead Generation fall under marketing but are 2 very different things. Advertising and Public Relations are marketing, but again are disparate. The illustrated differences among branding, advertising, PR and marketing.
Back to Sales and Marketing. Marketing is the voice to the marketplace. Sales is the multi-step process of converting a qualified prospect to a customer. Sales and Marketing have to play together (see here), but they are not the same thing.
Some define marketing as determining what the marketplace needs / is going to need / should need and finding a way to satisfy that need and make a profit doing it. Marketing is even determining who the customer is. But there are 2 types of companies: sales-driven and marketing-oriented. Best described here, the sales driven company is constantly in close mode; pushing for sales; promoting its services. The marketing oriented business today is listening to the marketplace (social media anyone?) to deliver what the marketplace needs, even if that means tweaking its services or even its delivery of services.
To try to teach sales and marketing in the same session is crazy. Your MBA classes are mostly about marketing and finance (rarely about sales, listening or entrepreneurship), so how would you try to explain both in 45 minutes, when it is clear from the title you understand neither?