Understanding Chrome Extensions.

Hello, hope this is the right place to post this.
I created a Chrome extension and i understand it works beautifully, and recently received several emails from guys that are promoting their services and offering some kind of scheme where they guarantee X amount of installs for X amount of dollars.
Ive never seen that since it is my first time coding such a thing.
So the questions regarding this are about these guys and their emails.
Is it safe to hire them?
Are they snake oil?
I understand they could have x number of email accounts and download my extension and fake clients, but i dont know if thats really the case?
My extension has a 7 days free trial, so fake installs wont work at all.
Is it common to receive such offerings in the couple days after the extension is published on the chrome web store?
How could i best promote real installs?

Thanks in advance.

I'd be skeptical of anyone guaranteeing installs right after launch. Some providers are legit, but many deliver low-quality or incentivized users who never become paying customers. If your extension has a free trial, I'd focus on retention and conversions rather than raw install numbers. Real installs usually come from SEO, YouTube demos, niche communities, and content marketing targeting the exact problem your extension solves.

No, skip them, most are fake installs and dead traffic.

Those services are focused on boosting install numbers, not bringing real users who will actually use and pay for your extension.