1. Very few people make real estate transactions as frequently as once a year, let alone daily.

2. The amount of money involved in a real estate transaction encourages prudence and due diligence.

3. Every piece of real-estate is unique. That means that acquisition always entails tradeoffs and opportunity costs.

4. The real-estate sales market has aspects of a highly competitive commodities market. This means that ultimately, technologies that improve efficiency ultimately result in lower prices across the industry. For example the internet has tended to lower real estate commissions as sellers are more able to market properties themselves and to are better able to negotiate with multiple agencies.

To put it another way, what's the business case?