I have a suggestion for a service which I believe could be quite profitably. The service should be run in collaboration with a map application service. My suggestion is that every time a user searches for a particular location; e.g. a club, bar, or restaurant, a panel alongside the search results should indicate the number of patrons intending to visit the establishment on a particular day. For example, if I were to decide to attend a particular nightclub on a given evening, I would go onto the service, search for the venue's name, and click something that indicates that I intend to be there on that particular evening.
As the number of service users increases, the application has the potential to offer each user the opportunity to gauge how many other people are intending to visit a particular establishment on a particular evening. With clubs for example, an empty establishment can ruin an evening, whereas an overly full one can have similar effects. It may also provide an indication of whether a restaurant is likely to be full on a given evening. Conversely, it could simultaneously be used by businesses to gauge the number of people that may attend their business on a particular evening, thus helping them with staffing level issues etc.
From a revenue perspective, advertisements could be sold alongside these search results, working in a similar manner to how sponsored links currently offer companies marketing opportunities. I would suggest that the advertisements in this case would be more establishment specific. This may afford a greater ability to generate more focused revenue. I would recommend monitoring IP addresses to ensure that the same individual is not clicking constantly, as might be the case with competitors etc, simply to alter either their own, or their competitions attendance levels.
What would be important in this particular instance would be the creation of critical mass. Once that is achieved, despite possible service replicability, users would invariably flock to the platform with the highest number of unique users. I would be interested in hearing any thoughts concerning the above.