observed that e.g. /r/MegaLoungeV is a highly-active sub, which isn’t necessarily what you’d expect if the activity level was based
entirely upon the number of people permitted to have access.
I started wondering if there might be a better predictor of engagement levels. I experimented by looking at the ratio of how many people ‘subscribe’ to each MegaLounge to
how many people are permitted into there. This isn’t a perfect measure of engagement, of course, but my thinking was that of the people who are invited into a MegaLounge, only
some of those will add it to their front page… but that those who add it to their front page are more-likely to actively participate.
The graph shows three things. From the left axis, the blue and red lines show the number of people who are allowed into each MegaLounge and the number of people who are
subscribed to each MegaLounge. As you might expect, there’s a gap between the two and the gap narrows in higher lounges, where there are fewer people.
But what I was interested in is whether and where this gap changes proportionally: is the “subscription rate” among eligible people higher in particular lounges, and can this been seen
as a predictor of activity levels and engagement rates in each lounge? That’s what the green bars show (against the right-hand axis: note that it doesn’t start at zero). In general,
across the MegaLounges up to and including /r/MegaLoungeSol, there does seem to be a slight upward trend: i.e. the higher a
lounge you’re in, the more-likely that eligible people are to add that lounge to their front page. Beyond /r/MegaLoungeSol the bars
jump around all over the place, probably because of the small number of people ‘up there’, and I suggest that we ignore them: accuracy of this as a predictor would be expected to be
better where there were more subscribers: say, up to about /r/MegaLoungeDiamond.
What this would predict would be a “lull” at /r/MegaLoungeVIII. I don’t know if that’s your experience or not. And, interestingly,
the ‘subscription ratio’ at /r/MegaLoungeV and /r/MegaLoungeX are also unusually
low, bucking the overall trend. What does this mean? I don’t know. But if /r/MegaLoungeV really is to be considered one of
the more “active” MegaLounges, then I think that we can safely say that my hypothesis – that we might be able to predict activity hotspots by looking at the subscription rate – is not
backed up by the data.
It’s been almost five years since Sainsbury’s supermarkets pioneered the “brand match” idea, which rivals Tesco and Asda later adopted into their own schemes, and I maintain that it’s
one of the cleverest pieces of marketing that I’ve ever seen. In case you’ve not come across it before, the principle is this: if your shopping would have been cheaper at one of their
major competitors, these supermarkets will give you a voucher for the difference right there at the checkout. Properly advertised (e.g. not in ways that get banned for being misleading), these schemes are an
incredibly-compelling tool: no consumer should say no to getting the best possible prices without having to shop around, right?
But it’s nowhere near as simple as that. For a start, the terms and conditions (Asda, Sainsbury’s, Tesco) put
significant limitations on how the schemes work. You need to buy at least a certain number of items (8 at Asda, 10 at the other two). Those items must be directly-comparable to
competitors’ items: which basically means that only branded products count, but even among them, the competitor must stock the exact same size or else it doesn’t count, even if it would
have been cheaper to buy two half-sized products there. There are upper limits to the value of the vouchers (usually £10) and the number that you can use per transaction or per month.
“Buy X get Y free” offers are excluded. And there’s a huge list of not-compared products which may include batteries, toys, DVDs, some alcoholic drinks, cosmetics, homeware, flowers,
baby formula, light bulbs, books, and anything (even non-medicines) from the pharmacy aisle.
But even if it only applies to some of your shopping – the stuff that’s easy to directly compare – it’s still a good deal, right? You’re getting money back towards what you
would have saved if you’d have gone up the road? Not necessarily. Let us assume that on average the prices of these three supermarket giants are pretty much the same.
Individual products might each be a little more expensive here and a little cheaper there, but if you buy a large enough trolley-load you’re not going to notice the difference.
Following me so far? What does this mean for the voucher: it means that it no longer remotely represents what you would have saved if you’d actually been “shopping around”. Let’s take a
Suppose that this is my somewhat-eccentric shopping list (I wanted to select a variety of comparable branded products), and I’m considering shopping at either Sainsbury’s or Tesco:
Crunch corner yoghurts
Cadbury Mini Rolls
Frozen petit pois
Goodfella’s deep pan pizza
Dry white wine
Red Bull multipack
Not too unreasonable, right? I’ve made a spreadsheet showing my
working, where you’ll see today’s prices for each of these items (along with the actual brands and package sizes I’ve selected), if you’d like to check my maths, because here comes
the clever bit.
Based on my calculation, taking my imaginary shopping list to Sainsbury’s will ultimately cost me £52.85. Taking it to Tesco will cost me £54.13. Pretty close, right, and I’m not likely to care about
the difference because Tesco would give me a £1.28 voucher off my next shop which makes up for the difference (note that Sainsbury’s wouldn’t reciprocate in kind if it were the other
way around, after a policy change they made late last year). But that’s not
actually a true representation of the value of ‘shopping around’. As my spreadsheet shows, if I were to buy each item on my list at the supermarket that was cheapest, it’d only cost me
a total of £43.75: that’s a saving of £9.10 (or about 17% off my entire shop) compared to the cheapest of these supermarkets. These schemes don’t give you a
real “best of all worlds”. Instead, they give you, at most, a “best of all worlds, assuming that you’re still going to be lazy enough to only shop in one place”.
If you’re particularly devious of mind, you can exploit this. For example, suppose I went to Tesco but when I reached the checkout I split my shopping into two transactions.
The first transaction contains the frozen goods, milk, wine, dough balls, flapjacks, and mini rolls. This comes out at £33.73, which is £10.38 more than Sainsbury’s would charge me for the same goods. Tesco therefore gives me a £10 voucher, which I
immediately use on the second batch of shopping: the one which contains goods that are cheaper than their Sainsbury’s equivalents. The total price of my shopping:
£44.13 – only 38p more than if I’d gone to both supermarkets and bought only the best-value
goods from each (the 38p discrepancy comes from the fact that Tesco won’t ever give you a voucher worth more than £10, no matter how much you’re losing out).
It’s not even that hard to do. Obviously, somebody’s probably written an app for it, but even if you’re just doing it by guesswork you can get a better result than just piling all of
your shopping onto the conveyor belt together. Simply put the things which seem like a good deal (all of the discounted products, plus anything that feels like it’s good value) at one
end of your trolley, and unload those things last. Making sure that you’ve got at least ten items on the conveyor, ‘split’ your shopping somewhere towards the beginning of
these items. Then take any voucher you get from your first load, and apply it to the second.
It’s pretty easy, so long as you don’t mind looking like a bit of a tool at the checkout.
But to most people, most of the time, this is nothing more than a strong and compelling piece of marketing. Either you get reminded that you allegedly “saved money”, on a piece of paper
that probably goes into your wallet and helps to combat buyer’s remorse, or else we get told that we paid a particular
amount more than we needed to, and are offered the difference back so long as we return to the same store within the next fortnight. Either way, the supermarket wins your loyalty, which
– for a couple of pence on each transaction (assuming that the customer doesn’t lose the voucher or otherwise fail to get an opportunity to use it) – is a miniscule price to pay.