I use Ytranker every month to get new subscribers and likes on new YouTube channels. I identified the following advantages and disadvantages. Pros: always active, many available channels for advertising, fast promotion, minimum bots. Cons: you need to carefully compose a brief on a narrow topic of the channel, so as not to get an account blocking, not always the target audience.
These shortcomings apply in general to such systems. Excessive cheating quickly leads to blocking, so we fit into the daily limit. In parallel with this service, I use promotion in other advertising services. So far, I haven't come across sanctions from YouTube, so you can use it.