A colleague tweeted at me the other day: Why would the Redfin app produce a dialog on his iPhone that read “Location Accuracy: Turning on Bluetooth will improve location accuracy”? Redfin is both an real-estate broker and an enabler of property sales by an owner, but I’d never seen this message before. I was stumped. Colleagues of my friend, however, figured out it was Redfin’s use of iBeacon, Apple’s technology for Bluetooth-based local-information markers.
Apple uses Bluetooth as one of several markers to pinpoint location. GPS may be primary, when a clean signal can be acquired, but cellular, Wi-Fi, and Bluetooth can provide more granularity. Every cell tower’s location is fixed and typically has a known, highly precise set of coordinates available. Wi-Fi signals get gathered through all of our collective use of iOS devices taking snapshots of Wi-Fi network names and relative signal strength around us. Wi-Fi networks generally remain fixed over periods of time. (Have you ever moved, set up your Apple base station in a different time zone, and seen your iPhone acquire the wrong local time? That’s why.)
Bluetooth is a different use case, however, because Bluetooth almost always roams with a device. iBeacons can provide a fixed location, such as within a retail store, that are mapped against geographic coordinates and can help provide precise indoor location information. Redfin isn’t using that aspect, but its app causes iOS to pop up with that message if Bluetooth has been turned off because it uses proximity features.
Apple limited iBeacon to working only with installed apps—there’s no generic way to trigger a pop-up coupon. That may have restricted its deployment. I’ve never used any app that was triggered by one, although it could be useful for boarding passes and retailer-related Passbook cards. (In the Starbucks app, a location marked as a favorite brings up a notification based on geofencing, rather than Bluetooth or Wi-Fi.)
How Redfin uses iBeacons
Redfin began testing out iBeacons in December due to the initiative of one its software developers, Audrei Drummond, who blogged about how the firm employed the technology and some of the practical limits they bumped up against. With my privacy hat on, I spoke to Redfin about the choices they’d made in building out this feature and how they manage information collected about users of its apps.
Bridget Frey, the chief technology officer of Redfin, says of its customer, “They don’t want to see every single home. They want to see the home that interests them. Maybe even the home they’re standing inside of.” Instead of creating custom hardware, Redfin opted to turn the iPads used by agents and homeowners into temporary iBeacons.
This has two beneficial aspects. First, the iBeacons aren’t enabled all the time, which limits the ability of passers-by with malicious intent to attempt to hack embedded firmware, which could otherwise be useful in dense areas where a lot of Redfin properties were listed. Redfin app users, people seeking homes, would be very nice targets.
Second, because the iBeacon arises out of the custom selling app and not in separate hardware, updates for security flaws or other weaknesses get pushed out to all users at once.
Drummond says she looked into using geofencing—geographic-coordinate based location alerts, but Apple only allows apps to monitor up to 20 of these at a time, although the geofences can be swapped in and out. With Redfin’s density of usage, that becomes a management problem. Instead, Redfin is using “beacon regions” that alert an app in the vicinity when the right parameters match an installed app.
The app will let the user pull up the house listing they’re in via a notification or with the app open, but Frey says Redfin doesn’t store any information about a house visitor’s interaction over Bluetooth. The firm measures a lot of parameters around people using its app, but didn’t want to associate location and other information together. “We felt like this isn’t for us about measuring the number of clicks, but about whether we can delight some of our customers,” she says, leaving some analytics on the table.
Redfin has a motivated audience for this use: Potential home buyers have installed the app, and may be using it for custom alerts about houses hitting the market. Frey says that speed is a huge issue, because of the high demand in some market for houses. This leads users to be more comfortable sharing more personal information with Redfin that helps them jump on a match more quickly.
I wager Redfin may be conducting the largest single-firm deployment of iBeacon globally—it’s hard to find any other stories beyond trial efforts, some a year or two old. And by using iPads as iBeacons rather than custom hardware, the firm avoids that pitfall of maintaining and updating separate gear.
It seems quite positive that Redfin has considered the privacy aspects and decided definitely what kinds of data associated with iBeacon to discard, and a deployment that minimizes a number of related risks.
However, there’s one kind of Apple technology they have no plans to implement: You won’t be able to close on a home with a fingerprint and Apple Pay. At least not yet.
Author: Glenn Fleishman, Senior Contributor
Glenn Fleishman’s most recent books include Take Control of iOS and iPadOS Privacy and Security, Take Control of Calendar and Reminders, and Take Control of Securing Your Mac. In his spare time, he writes about printing and type history. He’s a senior contributor to Macworld, where he writes Mac 911.