There’s some great background information on the Physical Web in Statler Consulting’s interview with Scott Jenson, Google’s Project Lead for Physical Web.
The interview explains how the Physical Web has been devised as pull not push so as to ‘respect the user’s attention’. It’s expected that the Physical Web will see slow but steady uptake in a similar way to WiFi. It’s intended that, much like WiFi, people will see the Physical Web logo and take out their phone. It’s NOT about them getting a notification that causes them to look at their phone. It’s believed that larger rollouts like those for Transport for London will build awareness of the logo. It’s still early days and if you don’t like this model then you should wait until/if it becomes successful rather than expect it to provide spammy notifications.
The interview explains how Google would obviously love Apple to build the Physical Web into iOS – something they might do if it becomes popular. There’s also an explanation that https is needed to prevent snooping and MiTM attacks.
When Chrome, the Physical Web app or Android detects a Physical Web beacon it needs to obtain information about the destination web page, for example the title and logo, to present to the user. This doesn’t happen directly. Instead a Google proxy server provides a level of indirection that caches information and enhances privacy for the user. It’s the Google server that gets the initial title and logo information for a web site thus allowing rogue sites to be potentially filtered out and preventing the destination site from deriving any information from the initial discovery. It’s only when the user taps the link (with fetched title and logo), that Chrome, the Physical Web app or Android causes the web site to be actually fetched into the phone’s default browser.
Of course, the result of this is that Google itself can collect lots of metadata about Physical Web use. If you think about it, as Nearby also works with iBeacons, Google must be sending ALL encountered beacon ids up to its servers, even those that aren’t Physical Web beacons so that it can determine which are physical web beacons. All that extra data could give a very useful picture of general beacon use.
Looking at it from another direction, it’s possible to imagine a dystopian future where the Physical Web proximity list might come with contextual adverts. Having said this, any significant interested party, for example Opera being a current case in point, can choose to implement their own proxy so Google doesn’t necessarily control all of the Physical Web. Might such a point of control also be attractive to Apple?
Meanwhile, Google is saying the Physical web is open and built like the web to encourage adoption. Even the Eddystone URL web proxy is open source.
So what of the future when there’s the possibly too many beacons at a location? The Physical Web team is currently investigating filtering schemes such as starring, showing top x, popular (frequently tapped) and even searching.