I was going to say the same thing. This whole thread of comments seems focused on $5/month. I don't even host a blog on that one ($10, I'm not fussed paying 5 bucks more to ensure it stays up on the off chance I write something people linked to). $5 offering really is the marketing line to get you looking at the offering IMO.
Equally, at our company, we're paying DO for many different machines at $160. I'd love to know their ARPU number, I expect it is actually significantly above $5.