I guess you can. Email seems to be more popular, though. For any given person, there's a higher likelihood they have email than any particular IM client.

Not at a local level.

In many countries in Europe, WhatsApp is just about ubiquitous, and used by the average guy way more often than email.

The same (from what I understand) for WeChat in China.

Yes, if you need to communicate outside of your local circle of family and friends, e-mail is still king (for business communication for example, no contest), but how often does the average guy does it?

I'm a little shocked at your experience. It doesn't match my experience. Literally everyone I know has an email address.

Yes, everybody has an e-mail address, I'm talking about day-to-day communication and how much each medium is used.

My brother/sister/mom/friends might use the e-mail once or twice per day, while they would use IM on mobile dozens of times per day.

When you see people on public tranport or on the street writing on their mobile, what do you think they are doing?

Most of the time they are using some kind of IM, not writing an email.

I agree that more people have an email address than a particular IM client, however, a lot of people outside of the tech bubble don't use email much anymore for personal communication.

iMessage is the solidified IM platform I see most, as if you have an iPhone, you have iMessage.

In Australia SMS is still widely used because of IM fragmentation. A proprietary IM platform will never take over and we will stay in the current mess until one of the open source standards become well used.