From public radio to free music streaming, advertising has long subsidized services so that we can enjoy what they provide without having to pay for them. Now, Google has a new idea that could bring the advertising model to taxi cab rides, a concept that could save some people a fair chunk of change on cab fare.

Of course, not everyone would be given the special treatment of a free taxi ride, and the Google cab might not become a reality for awhile anyway. According to a report from TapScape.com, the search engine corporation was recently awarded a patent by the U.S. Patent and Trademark Office for the concept of “ad-based taxi services.” As outlined in the patent, the service would allow customers to receive free rides if and when they are heading to the advertiser’s store, restaurant, or place of business. In essence, the business would pay taxi fares to get more customers to their location and through the door. Ideally, customers would then spend the money they would have spent on transportation – and then some – at the business in question.

Of course, businesses wouldn’t exactly be interested in ferrying window shoppers to their location. The Google taxi service would therefore take advantage of a number of calculations and statistical models to predict which customers would spend the most money at certain businesses. Those customers would then be the key targets of advertising programs related to their interests and spending habits, and would therefore receive better transportation offers than other, lower paying customers. The system would also take distances and travel times into account to determine how much the taxi rides would cost and how likely the advertiser would be to make that money back in sales at their place of business.

Customers interested in getting free taxi rides – in other words, every person who lives in a big city – would be able to view different advertising offers and promotions through their phones or at kiosks that would, supposedly, be placed around areas where the service is offered. For instance, a customer looking to head to Macy’s, Best Buy, or a restaurant uptown could check into promotions offered by those businesses and request a free taxi ride.

Given the attractiveness of free taxi rides, it seems as if Google’s latest idea could be easily manipulated or abused by freeloaders. Before the taxi service can become a reality, the company will have to answer a number of questions, including how it will ensure that customers are actually being honest about their destination. As is, someone could apply for a free ride to a store or restaurant, but there is no way to really ensure that the person is even entering that store or restaurant, let alone spend lots of money there.