You get 1 free month of Perplexity Pro by clicking on the referral link at the base of this post.
Where it says REFERRAL LINKS below, click on where it says "random" next to the word Referral. This will give you a random referral link for one month free of Perplexity Pro. The referrer will also get a free month too.
When you signup, you can also refer family and friends up to 12 times. Each time, you both get a month. So if you started with one here, you can get up to 13 months free.
I can remove this post if necessary, as I realise there's already a referral deal for this on Ozbargain. Though it's got the wrong title, it says "Referrer and referee get $10 credit", it should be "Referrer and referee get one month of Pro". I believe Perplexity upgraded the deal from $10 credit to an entire free month.
Edit: I'm not sure how to actually remove the post! But I'll remove my referral link.