When people don't buy (even after they've expressed "interest") it generally means there's a problem with one or more of the following:
1. Product Positioning
2. Creation of a compelling (aka irresistible) Offer
3. Proper Pricing
4. Clear identification of your Market

To "sell" your product (i.e. to get more sales) you need the right message put in front of the right market with the right offer and priced properly in order to have the greatest probability of them buying.

There are always other factors (such as where they are in the buying cycle - for example perhaps they are just "shopping") but your strategy should take that into account.

And once you've figured out how much you can afford to acquire a customer (and other such key metrics) you are well on your way to growing your business.

My best advice is to consider that you don't "get" a prospect to buy. Get to know your market so well that you deeply understand what they want - then position your business and products to provide that to them.

In other words - Build a strategy around HOW your market buys and then make it easy for them to do so.

I'd be happy to walk you through the steps you need to take to create this strategy in a call.

In any case - I wish you the best of luck!