It's never really about YOUR product or service.  Clearly, what makes someone your customer is the fact that they are paying money for your product or service - but the reasons behind their willingness to pay are not so much to be found in the "bits and bytes" of your offering.  It's not about this feature or that one.  It's about the link between your offering to their business strategy and objectives.

Nevertheless, the bigger the offering and the more expensive it is (think about the highly complex technologies being offered by companies lie HP, IBM, Siemens, etc.) the more complex the sales presentations seems to be, providing an overwhelming amount of technical details.  This is not effective and at times even destructive to the sales process.

no matter how complex, innovative or advanced your offering is - the key to your success in the sales process lies in your ability to clearly and concisely demonstrate their relevance to your would be client's  BUSINESS objectives and strategies.

You can be several people to your customer, in context of their relationship with you.  At the very start, you are seen by them (and frequently by yourself as well) as a mere PROVIDER.  This means that when they are ready to execute on decisions they have made, when this execution calls for products or services you can provide, they turn to you.

But if you manage your interactions with them properly, your informal (intuitive) status with them can grow to TRUSTED ADVISOR and even BUSINESS PARTNER.  This will be manifested by the stages in their decision making process (long before actual operational execution is required) in which they invite you to participate in.

The earlier in their decision making processes you are involved and the more important (strategic) decisions that you are invited into, the more influence you will end up having on your clients (and internal customers).