15 July 2007

it's just a phone!

One-in-three Americans want iPhone -- or so Macworld claims. (Yeah, they're not biased at all.)

It's very thinly veiled advertising; in two clicks from that article I found the original press release from the research company. The "article" says:

Lightspeed Research surveyed 39,000 people on its US online panel in the days following the launch of the device on 29 June - and the research findings are staggering.

I'm not sure if I trust this "online panel". For one thing, as a friend of mine pointed out, people who are online are more likely to want an iPhone. Second, the "article" goes on to say:

Thirty-two per cent of those surveyed who do not currently own an iPhone stated that they do intend to purchase one, with 8 per cent planning to purchase in the next three months and 22 per cent planning to purchase "some time in the future", the researchers said.

First of all, 8 plus 22 isn't 32, and even with rounding error that doesn't work out. More importantly, though, there are plenty of things that I've said I was going to buy in the future that I never ended up buying; if I put off buying something for long enough then I realize that I don't want it after all.

My friends seem like the sort of people that would want iPhones, and I think that not even one-third of them would want an iPhone -- although now I'll ask around.

Furthermore, you don't need to ask 39,000 people to get these sorts of results. But it sounds more impressive if you do. Most polls for, say, political campaigns have a sample size of about 1,000 and a 3% margin of error. With a well-chosen sample of 39,000 you should get a margin of error of about 0.5% (the margin of error scales as the inverse square root of the sample size), but I doubt this sample is well-chosen. I suspect that Lightspeed Research (the polling company) wasted their time asking this many people, because their sample is no good. They claim it is at their FAQ, and I believe their claim that the demographics of the panel are the same as the general population. However, they say that "A panel is comprised of people who have opted-in to share their views on products and services and recruited solely for market research purposes." The sort of people who are likely to be in such a panel are people who spend too much time online -- exactly the iPhone's target market!

The moral of this story: just because you asked a lot of people doesn't make you right.


Anonymous said...

Just randomly, the other couple percent might be people who picked a time scale other than "within 3 months" or "eventually" that they just chose not to mention. They don't always give complete breakdowns of such things.

The Probabilist said...


that seems unlikely to me, because although 8+22 isn't 32, it is 30. Somehow I doubt that, if 32 percent of people are going to buy an iPod, the number of people who plan to buy an iPod in some definite time frame which is longer than three months is as small as two percent. A lot of those people will probably buy it for Christmas.