The addressable market that you calculate for your business may be smaller than it was for the companies that you intend to displace.  Disruptive technologies often reduce prices offered to consumers as processes are often more cost effective.  If your company lowers prices, it will likely shrink the addressable market.

However, the lower prices may enable new customers to purchase the product or service increasing total market quantity.  This effect drives an expansion of the adressable market.

The decline in price and the increase in quantity each have the opposite effect on the size of the addressable market.  The net effect varies by industry.

When presenting your analysis, justifying the increase in quantity is more difficult than explaining the decline in price, making it difficult to get VCs to believe that the net result is a larger market.  As a result, entrepreneurs that believe the smaller addressable market is sufficently attractive first present the smaller addressable market and then suggest that there is a potential for significant upside.  This is done to avoid unnecessarily making claims that a VC may find faulty, which may impact a VC's perception of management's competency.

If the attractiveness of your business is dependent upon presenting a larger addressable market opportunity, be sure to provide significant objective evidence that demonstrates the potential for increased quantities, as this will likely be a key assumption that VCs will focus on understanding.