I dont play hearthstone personally, but I do enjoy watching streams. I typically hang around 3-4 different streams, and I've been seeing very odd numbers some specific streamers, so I did some investigations.
I'll warn you that Amaz's stream has been filled bot viewerbots, despite the fact that he has been streaming for few months, and does have his own followers that is pretty large. You can find his stream at www.twitch.tv/amazhs.
Now, I'm not saying that Amaz is 100% viewer boosting. He has good number of viewership coming from real viewers. I expect his bot viewership be somewhere between 5000 to 8000 out of total viewers he get as of 5/07~5/21 investigation. I don't know if he was doing this before(I noticed but did not do investigation until 5/07).
1. His Numbers doesn't affect other streamers at all, until he hits 10k+ in concurrent viewers. I have seen him streaming at same time as other streamers such as Kripp, MaSsan, Reynad, and etc.
When Kripp or MaSsan is streaming already, Amaz typically goes up to 4k within an hour, 10k within 3 hours. During this, neither of their viewership is affected, and total viewership on HS goes up from 20~22k to ~30k,or even up to 35k, regardless of hours that he streams.
2. His viewership does not watch other streamers after he's done streaming. I was watching Amaz on May 15th, 2014. He had concurrent viewership of 18.5K viewers, kolento at 5K.
Amaz went off, and kolento went up to 8K viewership within an hour. Typically, you'll see this out of channels with 10K viewership or so, not from 18.5K viewership.
On 05/18/2014, Amaz was streaming along with kripp. When Amaz went off at 6:05 AM EDT, total viewership from HS went from 28k to 17k, and this went up to 20k in about an hour(at 7:00:AM EDT). Which is expected since there is a rise in viewership as night passes.
Compared to when Kripp goes off(25k to 20k, then up to 22-23k within an hour was sample I took), this seem to be drastic.
3. He uses chat bots. I use mIRC to track channel viewers. Then I saw something that I never saw before in typical popular streams. Whenever I go into Amaz's chat, throughout his stream hours, I see increasing number of chatters such as below, which I don't see elsewhere often. Here are some examples:
I have list of 1500 chatters named this way and still increasing from his channel alone. I'm sure there are more than them in his channel that I can't find on my own. After that, I did some investigation, and found http://onlinestreambot.com/.
This website offers service where viewership+chat bot comes into your channel, and bots even can talk with random subjects, which fits for Amaz's channel. I requested 1 week service, and well, 10 out of viewer list above showed up to my channel which I have made newly. They asserted that they can boost up to 30k concurrent viewership via their support.
4. I found some moments where Amaz's channel viewership significantly drop, while looking into chat list etc. This happened over 10 times over my course of investigation(which is manually seen, not auto detected), which is 5/07~5/21. I suspect this out of his bot server resetting, or failing.
here's some moments, taken within 5 min of each other, as well as some of his viewerlist.
EDIT: Twitch bot detector on twitter is not ran by twitch, and only detects with significant viewership difference between viewer count and chatter count, hence with bot chatters it doesn't detect them.