They use auto comment that detects new posts or by keywords. Then then spam you with ugly comments. I think of it as a form of vandalism on my feed and will delete and report them as soon as I see them.
The sad part is many Instagram users do not delete spam comments and leave it there. It only encourages such garbage as an innocent party might click or follow the link. You are providing a free advertising medium for spammers and scammers. Worst part; is some even follow back such spammers. The hunger for followers and comments is telling.
In case you don’t know, many such accounts are probably robots and robots won’t look at your posts, like your posts or comment in a meaningful way.
I have always reported them and nothing was ever done. Neither were there any acknowledgements or feedback previously.
All of a sudden, from a few days ago, Instagram started sending back report receipts saying they have taken action and the offending accounts were deleted. All within the same day to boot. Kudos to Instagram for making the platform a safer and cleaner place.
So don’t just delete spam but report them as well. I take it that many do not even know that spam comments can be deleted. Methods for deleting comments depends on phone and OS. Some phones may require you to slide or swipe the comment, or to hold down the comment for options or to mark it as selected and then pressing the trash can.
Use reporting responsibly and ethically as some may be promoting a legit business like selling clothes or scarves. In that case, just delete the comment if you feel it is spammy. Some may just be promoting their own Instagram accounts to gain more followers legitimately .
How many you here on Facebook are also my Instagram followers? I can’t tell sometimes as your user name may be radically different. Let me know if I didn’t follow you back. My Instagram is at @tvsmithmy