Justin, IMO, it really depends on how badly they need new customers. I believe Amazon takes 20% of any bookings made through its service. That’s a big bite off the top, especially if it’s a smallish business. Amazon also has some other requirements that may burden a little operation.
If it’s a new business and/or one struggling to get a foothold in an area, it may be worthwhile to use Amazon to attract new customers. If I had a business where I could expect repeat customers, like a carpet cleaner, for example, initially attracting them via Amazon might also be a good strategy. When I talked to a couple of established service businesses local to me about this, they said they did not feel that they would participate because of the high cost.
I’d advise looking at the requirements and discussing the possibilities with the client before deciding whether it might be a good opportunity for them or not.