Sales vs. Marketing in Professional Services Sales is about convincing your prospects buy your services. It’s about closing business opportunities. Marketing is about offering the right services with the right benefits to the right prospects. It’s about creating demand. There are some functions within professional services settings that may be a part of either marketing or sales. Lead generation is perhaps the best example. In some firms, lead generation is a key part of the sales function. In other firms where the marketing team is more active, lead generation falls on their shoulders. The same is true for proposal preparation.