Member-only story
The prime placebo
What we actually receive for the extra money we pay for next day delivery is not necessarily what we assume it is
The other day, it was my daughter’s birthday, and as we could not visit her on the day my other half ordered some letterbox flowers for her. (These are flowers still in bud, packed in a flat box that fits ordinary letterboxes. No, I didn’t know such a thing existed either.) When it came to selecting the shipping, three next day delivery options were available: a free one with the ordinary post, and two premium ones at extra cost. Entirely in line with my expectations (as a behavioural practitioner), she picked the middle one. But was that premium option good value for money?
Probability play
The company helpfully provides some probabilistic background to the possibilities. The ordinary mail delivery is stated to be “90% likely to arrive on time” — i.e., the day after it is sent out — but we are also informed that “Premium delivery is guaranteed!” However, reading further reveals this guarantee is not quite iron clad — the premium delivery (an extra £5) is “99% assured to arrive on the chosen day”, delivered before 8pm (and before noon for the Morning Delivery option that costs another pound extra).
