We have a very complex B2B SAAS product. Customers expect to do a full trial and understand the product before they purchase it. We are happy to tailor the product for their specific needs.
Many good answers that I won't duplicate, however one additional thought: Have you analyzed the specific metrics around the customers who HAVE converted to paid to see how they used the product, what data they input, etc? If you can figure out what's common among companies that do convert you can then design your marketing funnel to make sure that people do those actions, for example with additional training and emails in that area.