Promote it on...
"Promote It on ____" "DM us___" "Email to promote it here ____"
Have you posted a really great piece of content you're proud of and get a notification that someone commented on your post, only for it to be a spam bot telling you to do one of the above?
Yea, us too.
I have good news though, as long as you don't actually do what they say, they are completely harmless.
You can choose to leave them there or delete the comments, either option is completely harmless. But if you do delete the comments, it does not affect your algorithm! Your activity is what increases your reach, aka when you go and make a substantial comment on another profile, watch stories, like posts, etc.
One thing to note, they are also trying to increase their visibility by commenting on people's posts, so if you do not want these kind of comments to pop up at all, you can adjust your privacy settings in the app itself.