What each one is for
In a channel you are the only voice. Subscribers read, react and can comment if you attach a discussion group, but the feed stays clean. It is the right place for a new collection, opening hours, a sale.
A group is a room. Anyone can write, which makes it good for questions, reviews and the kind of conversation that turns buyers into regulars, and bad for anything you need people to see.
Start with a channel when
You post more than you answer. A shop with new stock every week, a bakery with a daily menu, a creator selling a course. The channel is easy to run and never needs moderating. Put a button to your shop in the posts and let the orders come through the bot.
Add a group when
The same questions keep reaching you in private messages, or customers start asking to talk to each other. A group answers questions once, in public, for everyone. It also needs looking after: spam arrives as soon as a group is findable, so turn on CAPTCHA and anti-spam from the first day.
Running both
The common setup is a channel for announcements with a linked group for comments and chat. One bot serves both: it moderates the group, runs broadcasts, and opens the shop. In BotLaunch that is one dashboard, with modules switched on per channel or group.
What it costs
The free plan covers one channel with basic moderation, CAPTCHA and anti-spam, and never limits members or messages. Starter at $15 a month covers up to 3 channels, enough for a channel, a group and one more.