Is Google keeping a lid on my traffic?

[JackPowers]

Take a look at the image attached. It shows visitors from Google over the last three months for one of my websites. All in all, it seems fairly stable. That would be all good, if it wasn't for the fact that I've been backlinking the crap out of this site and for that reason have moved up a lot for my target keywords.

My main keywords are now pulling in 2x and 3x what they did 3 months ago, yet the total number of visitors from Google remains constant. I have looked into it and it seems that when I get more traffic from main keywords, I get less longtail traffic and vice versa.

This does bother me as it seems no matter what I do, Google won't send me more traffic. I wonder what will happen when I hit nr1? Will Google shut off all longtail traffic?

This is not a rant, I would like to know if anyone else have experienced something similar and what to do about it?

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