You need to be very careful with cookies. I wouldn't do it unless there's a real compelling business reason, and even then, when I've done it in the past, we did it with a totally different domain. Ex: I worked at yahoo travel, travel.yahoo.com, we did cobranded pages with vendors; cruise bookings happened on cruises.travel.yahoo.net

I've also seen integration specific domains get used, but ownership of the domain can get complicated, IMHO a subdomain is the right thing to use, but it shouldn't be your primary user-facing domain.

Sorry for long reply.

I think I need to give more context here.

So I own resume builder - resumefromspace.com

The guy approaches me and says he has some job postings. He uses some kind of aggregator to get those.

He displays them on big website (FAANG type). Let's say I type in "React engineer" in Bing search and they have employment TAB, where they show his job postings.

When user clicks on that posting he is redirected to jobs.resumefromspace.com/jobId=123 where they will see:

- Header logo - that would be my logo with option to create resume - Job listing - where they would see job listing - Apply button - button to apply

Why I like it. - I think job search is relevant to my site (resume builder) - I will have additional traffic (like 5k visitors - if they need resume built)

Why I don't like it - Google may rank be down (for some reason ???). I have a good amount of organic traffic & I really like my small project.

Thanks, Dan

Nobody legit approaches anyone to do this.

I wouldn't do it, that sounds sketchy. You'd risk domain suspension, maybe even legal issues depending on what they host on it.

As others have said, it depends on what you mean by "safe".

I've been asked for things like this with my domains before, and usually I've declined. Not for safety reasons, but for coherency reasons. If the redirect is to a site that is both on-topic for my site and the other site is noncommercial and/or by someone I already have a relationship with, I'm more likely to agree to it.

If it's a purely transactional thing where my only interest in doing it would be for some sort of reward (in money, attention, whatever), then I'm not likely to agree because I think it dilutes the value of my domain.

What is your definition of safe? You are now tainting your domain with whatever they end up serving on that sub-domain.

I would not do this without appropriate compensation and a written agreement, if at all.

What's the incentive for you?

Thanks for your replies, everyone. I added the context to get a clearer picture.

no have not seen any one

> Is it safe

That depends upon your definition of "safe".

Note that, for most web users, they will see "somepart.domain.com" as just another part of "domain.com", and so if there is something on "somepart.domain.com" they disagree with (say, adult content), they will blame "domain.com" and complain to you, and/or your registrar, about said content.

It probably is a way of circumventing some browser settings that like: ``` Isolate requests to First Party domains ```

It doesn't sound right, and honestly i don't need to tell you that they can change the contents there whenever they want, or start a mail server sending emails on behalf of your subdomain(?)

I mean i can see countless reasons not to.

Not to mention competitors who want to de-rank your domain.

The human nature is bad, "homo hominis lupus" said a guy....

is it safe depends on how you define safe did anyone did it yes