Is the ReCharge checkout flow separate from Shopify?

Yes. Even if you already have a Shopify transactional message opt-in configured, you’ll still need to go through the gist setup process again for ReCharge.

What happens if a customer opts-in to transactional messages but doesn’t provide their phone number?

The customer will not be opted-in to transactional messages, and will not receive a message about their order. While this may cause some customers to not opt-in who otherwise intended to, this will prevent any interruptions to your checkout flow in Shopify.

What happens if a customer who opted-in to transactional messages only also opts-in to marketing messages?

The subscriber will receive order updates after they make a purchase, and will receive marketing messages when you schedule a campaign or if the subscriber qualifies for an automated message.

The subscriber will always receive their transactional message, even if they’ve received a marketing message recently.

If a customer is subscribed to both marketing and transactional messages, what happens if they opt-out from transactional messages?

Customers who opt-out of transactional messages are automatically opted-out of both types of messages. Note that the opt-out rate for transactional messages is very low (~0.33%).

What happens if the reply-to-buy keyword is in the middle of a sentence? For example, "I would love to buy this."

Nothing will happen. In order to trigger the purchase, the customer must respond with only the BUY keyword.

Is the reply-to-buy keyword case sensitive?

No. BUY, Buy, buy, and so on will all trigger the purchase.