Good communication, quick response time. Interesting group of people.

I was contacted via Linkedin, supplied with CEO interview articles and video. After some brief research I responded with interest and was invited to a phone interview with internal HR recruiter. The position is not posted on their website, and the recruiter did not specify a title or provide description. I assumed it's expected given the start-up nature of the company. Without spending a lot of time, the website overall doesn't clearly spell out what they are about, but I learned that they are a social site targeted to "Gen Z" (age 13 - 30) who thinks that "facebook is what their moms use." During the interview the recruiter didn't give a whole lot more information about the company or the position (even with explicit prompt) but quickly dived into a specific problem the company want to address after I provided quick overview of my background. At the end of the call, I was asked to put more thought into specific marketing programs they could run in order to attract a specific segment and send my ideas to them in an email. 3 business days later, I followed up with a call to the recruiter to confirm that the email has been received. She then told me that through a (job?) fair and other channels they have found people with B2C (rather than my B2B) background. Feeling like I've been used to generate marketing program ideas, I asked why, even though my B2B background is listed in my linkedin profile and discussed during our call, that I was still asked to send her marketing ideas over email. I was given the same 'why we didn't pick you' reasons and that my ideas weren't as creative and suited for the targeted segment. At the end, I feel like I wouldn't want to work for a company that seems to be using interviews as an idea generation channel, so not getting an offer or getting to the next step of the interview process isn't a big deal anyways. I just want to post this, so if other interviewees pondered, like I did, why we are asked to develop marketing program ideas in an interview and over email, that they are not alone and think twice before spending time and giving away their precious unique ideas.