Product sale happens by marketing not by engg (features).
So marketing should start even before you come up with the product.
Sale a concept not the product. People look for the solution to their pain rather then having a product first and then looking at what it can do for them.
At initial stage, put more focus on online marketing rather then traditional one. Get some articles on the web regularly. When your product mature, your marketing material will also be accumulated till that time (and of course competitor as well). When the sales team will pitch the product to some customer, they will not be able to show the product in reference to competitor's product because of availability and time constraints. At that time it is the material accumulated over the time on the web that helps.
Your product may be useful for everybody in the world. but do not try to sale to everyone. Identify just one vertical and one market segment at a time for sale. Focus all your energies to make the product successful for the chosen ones. Though at technical level your product may satisfy everyone's need but to pitch to different verticals (and market segments), you need to create different stories. Having too many stories confuse everyone including yourself.
You may be having 100 features in your mind. Do not try to put all of them into the 1.0 product especially not the half backed ones. Go to market early with less but complete features. Again remember nobody can compare 2 products feature by feature all the time. If a feature does not work properly, competition will make a big deal out of it and you will loose in the market. Keep your road-map for missing features ready.
Programmers care least about looks of the product. Take the services of a user interface and interaction designer to carefully design UI and work-flow. Whatever story you are pitching in your marking material should come out of the product UI automatically. Users should not need to receive training or read help.
If you are creating something new, you can never be in pull market. So need to push your product; nobody will come to you to purchase. People wold like to try the product also before purchasing. Let people play with the product freely. The product trial has to be really quick. Nobody comes back after a day to try the product. People even do not like to provide their personal info (including email address) just to look at something. Try to come up with a process such that he customer is able to get a feel of your product without even giving email address and is able to try immediately providing minimum contact info.
Let some basic features of the product be available for free all the time for trial. This captures customers for you. Charge for the premium features and/or volumes. Having more customers on-board will also help you quickly shape your product and product road-map.
Your big prospects will always come up with a list of missing features as 'required' to avoid your sales person. Make sure that you listen to customers more than prospects. If you change your road-map and development plan based on these inputs, you will end up producing bad things. Such prospects always deny for purchase telling some other reason when you go to them after creating their list of features. Focus more on the people who are already using your product; keep them happy, they will do free publicity for you.