QR codes are still yet to prove their value. There have been several high profile trials of late; but have they been successful and what do you benchmark success against?
Mobile web consultant Terence Eden has pulled together some stats from a TfL poster campaign that links users to a real-time bus schedule.
These figures show that since going live in November, the QR codes have been scanned 4,500 times at a rate of roughly 70 times per day.
It should be said that the data, which was sourced using Google's URL shortener, is not entirely rigorous. TfL has not confirmed how many posters the codes are included on, but the stats provide an interesting look at how Londoners are reacting to the growing number of QR codes appearing on adverts around the capital.
Eden believes this is an impressive number of scans, though he says the only true way companies can gauge the success of QR codes is by benchmarking against their existing response rate.
A-B testing is the best method. You run an advert on one day with a phone number, then the next day use a QR code. Comparing the results of the two ads is the only way you can realistically gauge the success."
The ability to pinpoint the exact number of people clicking on a specific QR code is one of the technology's key strengths, as it is difficult to prove that the number of people calling a telephone line or going to a homepage is directly related to a normal poster campaign.
Interestingly the stats from the TfL posters also reveal which devices are being used to scan the codes – iPhone comes out on top with 45% of scans, followed by Android at 28% and Blackberry with 22%.
While Eden says the relative success of QR code campaigns have to be viewed within the context of a brand's wider marketing activity, it is interesting to compare the statistics against other QR experiments.
A campaign in the Metro which linked back to the newspaper's homepage achieved 17,000 scans in two and a half months, while a Boots campaign achieved 11,000 scans from people who wanted to find out more about a new skin cream.
In terms of sheer numbers, the TfL campaign would appear to be less successful than these examples, but the 4,500 clicks is huge when compared to the anecdotal evidence from a John Lewis virtual shop window which routed users to its website using QR codes.
PR agency Leapfrogg spent five hours observing shoppers outside the window over a five day period and only two people stopped to scan a code.
The John Lewis experiment ticked all the QR best practice boxes - busy location, good call-to-action and linked to a mobile optimised site - but on the face of it the results were far from impressive.
Up to now brands haven't been forthcoming with the results from QR code adverts, so it isn't possible to properly gauge how the public is taking to QR codes and whether the popularity is growing over time.
Eden believes that it is only a matter of time before consumers become comfortable using QR codes on a daily basis, and advertisers are certainly banking on that considering the number of codes that appear on posters and in newspaper ads.
However while actual data remains scarce the jury is still out.