Why does an app read my phone's IMEI number? An awful lot of them do

Question

What reasons should an app have to need my phone's International Mobile Equipment Identity number? I noticed that unreasonably many of ordinary apps have the "phone state and identity" permission. For example, Remember the Milk. What do they ask it for? Am I insufficiently paranoid?

Answer 1

Many apps use the IMEI for analytics purposes, for example counting users. Most tools like Google Analytics or Flurry need a unique ID per phone, so the IMEI fits quite well.

Note that this doesn't work on non-cellular platforms (like tablets), and the IMEI can also be faked: this is why some apps choose a different system (see this article).

Answer 2

It's often used to identify the unique phone, but often this is actually quite a bad idea. Most apps would be better off identifying you as a user, who can use multiple different devices on one account.