I think the service most people are implementing into their website comes from coin-hive.

It is an XMR miner, that uses a JS script to mine at about 70% power. Not too shabby for a browser based technology.

(Disclaimer: I do use the miner publicly on my own website, but have no affiliation with coin-hive.)

Basically, don't waste your time. The results aren't mind blowing, and are going to irk a lot of customers.

Currently in bitcoin terms, I think you get about 400 satoshis worth of XMR per million hashes solved? And the average hashrate I'm seeing is less than 10/ second.

So in exchange for more than 100,000 seconds of the customers time and effort, (Which would be over 24 hours? I believe?) you'd get 400 satoshis.

I am keeping mine, because it is a public profit share "mining" system that actually makes sense on my micro earnings site, but for most people. C'mon. You can do better than that. Just add a donate button, for pete's sake.

Just my 2 cents on the whole thing. I love the technology. I'm assuming they compiled a C++ miner using ASM.js, and whatnot?
So cool tech, gimmicky results, that'll make your customers mad, and won't get you any closer to a payout.

Thanks for the article. Upvoted, and will follow, since you talked about something cool, and techy. :)