A great example is GoToMyPC. It is a service that allows you to connect to your office computer from home. As an entrepreneur who likes to connect evening and weekends, I tried out the service and am on a free trial for 30 days. After connecting for the first time I knew I would become a member when the free trial ran out. It is easy to use and incredibly valuable for a business owner who wants to be able to get their files and use their computer from any location. If GoToMyPC can only get entrepreneurs to try out their service, they are sure to bring on a significant number of new clients - hence the free trial that got me hooked.
While it is true that someone who pays for your product is more likely to use it and value it compared to someone who gets it for free, I always recommend showing the price of the product and then offering a promotional free trial to show users that it is a valuable investment.
Offering something for free not only gives you a potential customer base to sell to but it can also give you positive PR (ie. celebrity endorsements) and can help you stand out as a good corporate citizen if you give your products to charity.
It is far easier for some companies to offer something for free depending on your product or service but regardless of your industry, try to find a low-cost way to give away a taste of what you have to offer for free and your small business owner prospects will take the bait. It will then be up to your product to deliver on its promises and your salespeople to close the deal. While small business owners are cost-conscious and like anything that is free, they do pay for what they value. It is up to you to clear through the noise and get your product in their hands.