Having worked in several sales and marketing roles, I know firsthand how closely intertwined they are. To increase sales you need to understand your sales funnel. In other words, what steps do people need to take to make a sale. When you determine this you can establish which points in their buying journey you need to focus your marketing efforts on. Check out my page on Marketing.
It's not just about the bottom line. It's the whole package.
I once redeveloped the sales toolkit for a luxury hospitality brand. I looked at what we could offer and what customers were asking for, and then I simplified the decision making process. Too much choice can be overwhelming and it can also lead to more work and resourcing.
The end result? Our customer's had a good - but limited - selection of choices. My sales team had a product that was easier to sell and the operations staff had a service that was easier to deliver.