Do companies sometimes use fake job interview to get free creative product or expert opinion?

I was doing a series of “writing auditions” for job at a start-up web service. Basically a freelance gig.
I think it was something like you sign up for this web service for free and you four-square style check in at a location and it will recommend things to do nearby food, timely events, etc.

The job was researching and then writing snappy little blurbs taht would be sent to people. At the third round of the ‘audition’ they were askingme to generate weeks worth of content.

I said ‘no.’ If they had stated that they were going to pay for the content I had generated in this audition process, I’d have a different story. It really did seem like they were using me for free labor and their carrot just wasn’t good enough.

On behalf of my employer, I require that people pass a fairly difficult editing test before I put them on our list of freelance editing resources. More than once people have hinted to me that they think we are trying to get them to do some editing work for free. This is not the case - the test was specially prepared for the purpose it serves, with errors and awkward use of language inserted to see if applicants can identify and correct the problems.

I don’t blame people for being suspicious, I guess, but it is a red flag when people act all snotty about it (this is not meant to imply anything about the OP or anyone else in this thread - I’m only referring to people I’ve dealt with IRL).