you mean $1 once when they first install it? the 'pay this amount' was a well known scam message

That changed. The app is now[0] free and it's $1/year, in every platform.

[0]: http://www.theverge.com/2012/12/20/3787472/whatsapp-for-ios-...

That's just free to download. You still pay per year fee.

Well I've been a user for 5 years and I've only paid my 0.99c fee. And I don't know anyone else who has had to pay a 'membership'

Android users pay an annual fee.

My first year free just ran out. They sent me a message that I get to continue for another year for free. It's hard to believe anyone pays for this.

Have you been a heavy user? I have a sneaky feeling that they will let light users have it free, but start charging heavy users. That makes sense, because if you are a light user, there is not a lot incentive to pay.

Due to network effects, it makes very much sense to let frequent users ride freely (perhaps not bandwidth hogs, but frequent communicators with multiple friends), as they'll bring in and keep many other users in the system.

I use it every day and I got my free account expiration date upgraded to "lifetime". Admittedly, I'm a light user regarding bandwidth usage; I do share some pictures, but probably a lot less than the average user. I honestly don't think I know anyone who pays the annual fee.

I'm an extremely heavy user, hundreds to thousands of messages and images per day, and I've had the same messages so I think it's the heavy users that they're allowing for free.

I think they don't charge countries that don't support payment on app store

That can't be right since the UK App Store supports payments and WhatsApp have never asked me for any money (but I was a light user before I ditched it for LINE.)

I wonder if this is significant in requiring that the person then has set up payments; that must lower the friction on getting those users then to buy other things or make further payments. The time and effort expended is probably for many worth more than the dollar spent?

I've had whatsapp since before it was available in the play store (they had a beta you would manually download back in like 2010 or 2009 or something) and I've never paid a cent... maybe because I signed up when it was still "beta"?

how on earth do they charge it if you don't have a credit card associated with your play account? Because I've used whatsapp for well over a year and can't figure out how they'd charge me.

I don't know, but they have your phone number. In the UK at least that can be done with a premium SMS.

Well , I did have to pay once. Your watsapp just stops syncing until you pay via Play.