Thanks for your response KTR. As was already said, great work detective!
It could be true and they already have experience but to be honest I also bought (cheap) studio lights and if you looked at my first video you might have noticed them too
I don't use them now though as it's a pain to set up and to make sure they don't reflect anywhere.
# Tags are used by many big channels now. I included them into my recent video and within 10-20 minutes after I published my video got about 20 visits in 10 minutes, which I later found came using #nurseryrhymes keyword
I'm now removed from search results for this keyword so getting zero search traffic.
I think you are right about "close tracker" - it's more about being very consistent and right on trend, with their thumbnails being the same as of big channels which of course copy it from each other too
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