Why pay for Live Chat when you have Facebook Messenger?

I have looking for embedding live chat on my site, but after seeing pricing, I went for Facebook Messenger.

Why ?

• Loved the UI,
• Facebook Backend Dashboard is cool
• Can redirect them to join my Facebook community (helps in growing community)
• I have them in my list forever without asking for emails (Using respond.io for broadcasting)

So I would love to know why people go for other solutions ?