Many of the prospects we approach in our investment banking practice are also potential customers or strategic partners.
The old saying that "an order solves a lot of problems" is really true for early-mid stage companies that are trying to accelerate or expand. Sophisticated investors (through their portfolio companies) and other strategic partners have the ability to evaluate the benefits and viability of a client's products / services from a business relationship perspective. That validation can lead to a large order, license, or manufacturing / distribution agreement that improves working capital, cash flow, and competitive positioning in the market - frequently without dilution.
It can be faster and easier to complete the due diligence and close on a business transaction funded from the strategic partner's operating budget vs. getting board and legal approval for a securities investment funded from their corporate treasury. A successful business transaction can also provide comfort to other prospects that someone smart has already completed the due diligence process and has made a financial commitment to the company's success.