submenow.comは安全ですか？

Please please avoid such fake. They are spammers. 1st you will get a chunk of subscriber and it'll be gone within a blink of an eye. No money back. You can try with a short amount if you don't trust me. But that's for sure you are not getting your money back

Yes, you get actual people viewing your youtube and hitting subscribe. The problem is quality control. Your view durations are super short which isn't helpful for your ranking. Almost every subscriber will unsubscribe. Some people even un-like! Paying only puts your videos at the top of the list so you will be seen faster. It also gets you clicks without having to see others videos/channels. Considering the quality control problems I wouldn't pay for this.

The service offered is very obviously against YouTube's Terms of Service. The whole point of this site is to purchase channel subscriptions or otherwise automate such a thing. It may not be illegal, but YouTube is very unlikely to say that they ban all subscription bots except for this site. Also, a number of YouTubers specifically identify this site as a common example of a sub bot site: *****