WhatsApp introduces ads in its app

I think that kind of business model will screw them. Line has a more sensible one. For example if a business wants to message all its followers, they can only do so twice a month unless they start paying. So customers get an ad-free experience and can only receive ad messages from companies or accounts they follow.

Meta are already monetising business usage of WhatsApp in this way[1].

Any ads are in addition to this, not instead of.

[1]: https://developers.facebook.com/docs/whatsapp/pricing/

There are most certainly ad banners in Line. At least in Japan. And they used to have some strange invasive bluetooth auto-connect when near a convenience store.