Awesome, yet disappointing at the same time.

My first impression was: “awesome!” and it’s a great tool if it works on your site. On my multisite however, I did not manage to get it going on more than one site per user.

Because it’s an awesome tool I spent a lot of time trying to solve this and was determined enough to even write a tutorial about it, while waiting for a reply. I never finished it though.

My enthusiasm cooled down when receiving this Rublon newsletter stating they would only protect one admin account per site. Anything more would cost $99/site/year.

I can understand the decision, but currently you can read in the description:

What Does Rublon Cost?
Nothing! The basic Rublon plugin is free and always will be. Premium features like custom branding are available through our paid Business Plan.

And in the FAQ:

How can I protect my account with Rublon?
Simply install the Rublon for WordPress plugin and activate it. After activation, all accounts have instant protection with email-based, two-factor authentication.

I would consider to pay $99/y for my multisite, but Rublon confirmed through email:

You’d require a seperate license for each website, but you can purchase bulk licenses for 100 or more websites.

That is not an option for me. So, basically, they break their word and by doing so they wasted my time.

Still, if you have a WordPress site with only one admin, or if the business edition is an option for you, Rublon is a great plugin. I however do recommend to take a look at the Simple Security Firewall as well. I’m currently also struggling to get it going on my multisite, but it does work well on the main site, so it should go smooth on single installs.