Careful which chatbot you talk to, unless you want their ads on Facebook Messenger

Brands and businesses can send 'sponsored messages' to anyone who has previously chatted to them or a chatbot on Facebook Messenger

Facebook has begun allowing businesses to send users adverts on Messenger, but only if those users have previously made contact with the brand.

Part of Facebook's iteration of its Messenger chat service as a platform, announced at Web Summit in Lisbon, the change will mean that if a user ever contacts a brand that will open the door to that brand then sending them adverts through the instant messaging app.