[mrweasel]

That's not what he mean. The question is "Have you considered the alternative to charging for WhatsApp". The alternative would be advertising or selling access to user data.

My general take is that if you need advertising to monetise your product, then maybe your product isn't as good as you think it is. Most newspapers are a good example of this, if you need a ton of ads on your website to make money, maybe your not doing a good enough job providing news that people are willing to pay for. As service become more and more depended on ads, the quality of the product starts to take a back seat and in the end you end up with click bait.

Google might be an exception, they seem to have found a mix that people can live with, or perhaps they're just really good at hiding ads in plain sight.