Carrot Quest

I worked with them for a year and never learned how to warn them about unsubscribe mailings. Why do they switch them off - they don't explain, although they see that the mailings are not spam, but from a legal service. I do not advise to use them, you will lose money only.

In general, the service is workable, a good balance between price and features.
Closer, cheaper and clearer than Intercom.
I use auto-links (see below), popups, auto-messages, integration with messengers (do WhatsApp and classmates!), including Yandex.Dialogs and DialogFlow.
Very useful blog - I recommend it!
Unfortunately, it was not possible to make "all in one window" and run in CQ incoming messages, as DialogFlow has been known to reply to them, and this is unacceptable. They promise to fix it.
The initial implementation was done through GTM, then a few more events began to pass through the API.
There is a big "pitfall": suddenly began to turn off the sending of emails because of spam complaints (although they were not so much by the criteria, for example mail.ru). Technical support was not helpful, although they tried very hard. I had to install my own service for sending emails (Mailwizz) and set up integration between CQ and MailWizz via webhooks and other crutches.