From BHAG to MVP?

I have a big, hairy audacious goal of a project, but I am having a hard time figuring out how to carve out an MVP. There's a lot of potential for revenue streams, including brand marketing, subscriptions and lead generation, but they demand a large-scale project. I am about to launch a blog portion of the site, but can a blog "count" as an MVP? Should an MVP produce revenue, however small?

The "viable" part of MVP means people are willing to buy it.

Some folks argue it should be "buy-able" but that you should still give it away to reduce friction. I'm not one of those people; the difference between buying for very cheap ($20) and free is massive in terms of who you attract and whether you're really proving anything with your MVP.

Of course there's no one answer for how to carve out an MVP. But think about the "M" part. What's the easiest path to revenue?

Another way to think about it -- what's the simplest path? What's the way that's easiest to explain to someone else -- a friend, an investor, a customer, an employee? Not that you have to pitch it, just that it's a measure of simplicity.

Simple problems are still really hard; why pick a hard one to start out with?