You need instant credibility, which may mean borrowing some. That could come in the form of a strategic partnership with another person or company that is already highly respected in your industry. It may mean starting as an entrepreneurial arm of an established company. You could build your dream within a viable business, while leveraging a bit of their image--and money. A few years down the road, you could spin off into an independent company.
Another way: Grab credibility by certification from a known brand, such as the kind Microsoft offers software developers. Then you can say: "Our people are Microsoft-certified and have expertise in the latest Microsoft web hosting products.” The prospect will hear: “Blah Blah Blah Microsoft blah blah blah blah blah Microsoft blah blah blah.” And then they think, “Hmm. I’ve heard of Microsoft. These people are OK is they’re Microsoft people.” That is, unless the prospect is a Firefox nut.