IDEA: What should you be selling that you are not now offering? Ask your customers.

Start talking to inside sales people daily.  What do customers ask for your firm does not sell?  Are you missing sizes, colors, styles or various products that your competitors have started selling? Ask questions of both your inside and outside sales personnel and begin tracking their comments and items being requested by the public and buyers in your market.  The customers are telling you so you need to listen. Ask your employees and especially your sales reps (if they are listening).