Interesting concept, as a Wordpress developer since 2009, this spiked my curiosity. At first impression I figured this would be PHP based using the server for the hashes but then I noticed it said it uses Javascript which means it would run client side.. after looking at the coin-hive site I could confirm that this does in fact use Javascript so it's running on the client side and not on the server. So basically it's doing a small calculation in the browser of the visitor each time they load a new page. Unless you have hundreds of thousands of visitors everyday and even still, this wouldn't result in a very high throughput or hashrate. If you did have a site that popular, you probably wouldn't want to degrade the client's experience on the site with this and it would also slow down the page load time. If your site wasn't popular, you wouldn't want to use this because you'd want to focus on making your site popular because it wouldn't be effective and would slow down the site. Neat idea, but not very practical.