But some see them as fueling a disconnect from real human effort and interest on Instagram, even cheapening the platform. Calder Wilson, a professional photographer, wrote a post on PetaPixel, an industry blog, in April that described his two-year experiment with running an Instagram account that relied on Instagress to attract followers and likes. With only $10 a month and five minutes of his time per week, it quickly beat his carefully curated personal account on both measures.

Instagress enabled the user name @canon_bw to target users based on a long list of hashtags like #blackandwhite or #IGdaily, commenting on some with “Nice!” or strings of emojis. (These services can also target followers of large accounts like their competitors or, say, @nytimes.) In one 30-day period this year, the @canon_bw account liked more than 27,000 photos and left almost 7,000 comments, some of which led to enthusiastic responses. Mr. Wilson, 28, found it unethical, comparing “botting” to steroid use by athletes and lamenting the broader impact on Instagram’s culture.

Image Calder Wilson, a photographer, set up an Instagram account two years ago that relied mostly on automation services to attract more than 11,000 followers.

“If you’re a photographer trying to build a following or anyone trying to get your work out there and meet new people, when you get a genuine interaction, that feels good,” Mr. Wilson said in an interview. “When you have Instagress coming in there and leaving fake comments like ‘stunning photo’ and ‘stunning gallery’ and there’s no one behind it and then the likes — it’s as if they hijacked that personal neuropathway in your brain.”

Sara Melotti, another photographer, wrote a confessional blog post recently that outlined other methods influencers use to increase their numbers so brands will work with them. She said the practice accelerated after Instagram stopped showing posts chronologically last year and started ranking them by what its data said people wanted to see or click on. Many panicked after seeing their engagement drop after that, she said.

In addition to automation, she described buying followers, joining pods of 10 to 15 people who commit to liking and commenting on photos as soon as they are posted, and participating in bigger groups that coordinate posts and comments for the same time in hopes of appearing on Instagram’s “Explore” tab, where they will reach even more people.