The most significant research on this topic is the 2023 paper
Case Study: The Fall of a 500k Subscriber Channel
In 2022, a tech review channel (name withheld) with 500k subscribers decided to "accelerate growth" by purchasing a comment bot service. The service promised 5,000 targeted comments per day, each containing a link to the channel’s merchandise store.
She almost swiped it away. Her comment from two weeks ago—“Honestly, this mix is better than the studio version 🤷♀️”—had already gotten a few likes, a few trolls, nothing special. But the notification sat there, glowing.
Targeted Outreach: Bots often target the "First Comment" slot on new uploads to maximize the visibility of their links. Types of Bot Links Found in Comments
- TubeBuddy: A comprehensive YouTube management tool that includes a comment bot. https://www.tubebuddy.com/
- VidIQ: A popular YouTube analytics and optimization tool that offers a comment bot feature. https://vidiq.com/
- Social Blade: A well-known YouTube analytics platform that provides a comment bot. https://socialblade.com/
- H-Supertools: A free YouTube comment bot that allows you to respond to comments, filter spam, and more. https://h-supertools.com/
- Comment Bot: A simple, free bot that allows you to automate responses to comments. https://www.commentbot.com/
Thus, the "bot" part of the keyword is critical. It scales malicious activity beyond human capability.