There are 3 contributing factors for business failures, which are actually quite common in existing businesses today. The only difference is that established businesses have momentum and brand while the new business has neither.
Factor 1 - Clear articulation of value. This is not the value proposition (here's what we do / offer). This explains in very simple terms exactly how your product / service will help someone get a job done. Services are just harder to sell than a product because it is intangible therefore you need to go the extra step in getting your customer to understand how the service will solve one or more problems they are facing. You have to create an instant "visual" in their mind. Example: Suppose you are providing crisis management services for local communities. Your value prop would be "we offer crisis management services". But, your clear articulation of value is "We address the processes and reduce the costs (time, money, & effort) for crisis management so community leaders can address the needs of their community."
Factor 2 - Marketing & Sales. This involves establishing / extending your network (establishing is much harder and takes a lot longer to ramp up). If you have credibility, you're off to a good start and should be able to garner a few sales to prime the pipeline. If you are a new entrant in a field, then you have to establish credibility with pro-bono work and/or publishing and speaking opportunities. This can be a lengthy process (esp. in this economy). This is where most businesses fail because they need 3-6 months just to get their messaging right w/o professional services. Probably one of the hardest challenges the entrepreneur will face. This is much more intense than coming up with logos & taglines and websites. It's getting people to understand what you offer, what problems you will solve and why they need YOUR products / services. Price is not an issue at this point, credibility is everything. Set your price at a competitive level to cover your costs and discount as necessary to gain initial entry. Price will firm up as demand increases.
Factor 3 - Cash on hand. Well, this is what buys you time until you address Factors 1 & 2. Most folks don't have more than 3-6 months of cash available before they need to bring in revenue or close up shop. In a tough economy, double your ramp up time. If you have zero credibility, you may need to add 3-6 months of add'l time just to get the sales pipeline. That's a lot of cash and most businesses need luck or an angel investor to keep them going.
There's plenty of other challenges, but these are the foundational ones that must be in place so the entrepreneur can be positioned to address these "other challenges".