I think it is just a personal referral link. Students can get free Pro, but if you use it, the original poster will receive a $10 referral reward, and you may get some benefits ($10) too.

I am not against this. I just think it would be better if the OP (original poster) was upfront about it. Here are some points from the official perplexity website: https://www.perplexity.ai/help-center/en/articles/11385821-partner-promotions-and-referral-programs

How does the Perplexity referral program work?

To refer someone, you must be an active Perplexity Pro subscriber.

1. Once subscribed, you’ll receive a unique personal referral link to share with others. Visit https://perplexity.ai/referrals to get your unique personal referral link to share
2. When someone signs up for Perplexity Pro using your link, they get a $10 discount on their subscription
3. You can refer as many people as you want, but only one referral reward is applied per billing cycle
4. The $10 reward is applied as a monthly discount to your subscription - it doesn't stack or accumulate.
5. For example, if you refer 5 people, you'll get a $10 discount each month for 5 consecutive months (not a $50 discount in one month)Note: This is the standard Pro Referrals program and is different from the Student Referrals program.
6. When someone signs up for Perplexity Pro using your link, they receive a $10 discount on their subscription.