Businesses can now send you ads via text over Facebook Messenger
Now, it may not be as bad as it seems on first look. According to the Facebook Developer Blog post, these messages are "in-context ad type [message] that allows businesses to re-engage people who have an open, existing conversation with their business". The key words here are "in-context" and "existing conversation". Meaning, you shouldn't be getting spam out of the blue, but will get these from businesses with which you have been in contact with, and whose products actually interest you. The messages you will be receiving will pertain to new products or new promotions.
Also, Facebook states that customers will have the ability to opt in or out of Messenger interactions with the different shop pages, so you will essentially be able to block a service if it goes out of line with its advertising.
The social media is also introducing a new type of newsfeed ads. Advertisers will now be able to place a banner, which, upon tapping on it, can lead you straight to a Messenger chat with the service. This will most often mean a chat with a Messenger bot, which will give you information about products that interest you and any new promotions.
Facebook's ad revenue is currently doing pretty well, though, a loss of momentum is inevitable. To ensure a profitable future, the company does need to establish a solid platform that attracts businesses, sure, but it also needs to do so without disgruntling its users with disruptive ads. Thus far, it seems to be doing a good job. We'll see how this turns out in the near future.