Jason Fried has an unfinished post on difference between trying something and using something. Though he has not concluded it, I agree with his observation that most of the products today are made for trying, not using. If you are not sure think about the word demo in the software world. However I am not sure if it is because trying is more common, it is because trying is what makes the user pay for it. Most of the people are not ready to actually use it before they decide whether they want to pay for it or not, just too much effort.
The demo is important for converting the prospective buyer to a buyer. The experience of demo is what the user will use to do the cost benefit analysis. The demo is what will receive instant applause or awed expressions. However, it is more important to convert that buyer into a regular customer. Which can only happen if the buyer is happy after using it, not just trying it. And this can happen only if the product can provide the expected ROI.
I am trying to follow the Theory Of Constraints to look at ROI in software. Breaking a constraint can provide the maximum ROI. Not only for the sellers, but even the buyers can use this to identify which constraints should be broken and buy software with an expection of ROI.
I do not say that demos are only for showoff, they are also important for proof of concepts, or to simplify an explanation or to present a new idea. But the demo will have to be carried forward into a solid performing product to be able to get vindicated and provide some benefit to the user.
So why are most of the products built for trying? This is only out of my experience, sellers do not want to talk about the actual ROI. This is because that will make the prospective buyer think whether there is a need for it, which might not result in a sale. I believe that a lot of things we buy are not needed, we are just dazzled by them momentarily and then they lose place in our life. This is a losing proposition not only for the buyer but also the seller. Convincing the ROI can be tough and not dashing enough, but that is what will matter at the end of the day.