Hats off to Mark for putting together this great resource. We work with non-profits both as clients and as customers of our donation plugin, Charitable, so it's great to have a guide like this to help people out.

I think one of the great strengths of WordPress for non-profits is the ecosystem of plugins. Many non-profits need things like event registration, volunteer management, social sharing, donations, etc. — with WordPress, they can set all this up on their own platform for a very low investment. Alternative hosted platforms for non-profits are often far more expensive, particularly those that charge transaction fees to non-profits when they receive a donation.

Cheers,
Eric