Javascript Bitcoin miner is it even worth it? I know that mining bitcoins via JavaScript is just pointless at this point in time, but is there any other altcoin that is worthwhile mining via a GPU/CPU via a JavaScript embedded into a web page?

Our website gets over 2 million unique visitors per day, with an average time of 5 minutes on site. 

Is there anything we could do to get them to mine something in order to get even $0.005 per visitor? or is it basically impossible?
It is true that mining Bitcoins like this is impossible. (I can't speak for altcoins though.)
Let us run through a back-of-envelope calculation based on some facts and assumptions.


Network hash rate is 800 000 terahashes per second as of 2016-01-18 [source].
Remember that currently 25 BTC are rewarded every 10 minutes.
A modern consumer-grade CPU has 4 cores, and can calculate about 400 MB/s of SHA-256 per core in C. (More generous than JavaScript, but ignoring the upcoming Intel SHA Extensions instructions.)
One Bitcoin hash trial uses 2 blocks of the SHA-256 compression function (each block is 64 bytes), so this translates to 8 million hashes per second per core, and 30 million hashes per second per CPU.
One visitor donating 5 minutes of full-CPU time gives 9 gigahashes.
Multiplied by 2 million visitors per day gives 18 petahashes per day.
Meanwhile the rest of the Bitcoin network has produced 70 000 000 petahashes in a day and mined 3600 BTC.
The current price is 1 BTC = $400 USD. Your 18 PH out of 70 000 000 PH is 0.000026%, so this yields 0.0009 BTC reward, equaling $0.37 USD per day in total. But divided among everyone, this equals $0.0000002 per visitor.


With 2 million visitors a day though, why not optimize the ad revenue, user retention, conversion funnels, and other traditional online business techniques?