Welcome to the grind

Tes all you have to do is get the link you do not have to do anything with it, unless you want the free stuff then you can send it to someone who does not have the game downloaded.

Yeah, I assume at some point someone at Plarium realised that trying to get people to actually convince a friend to join in order to let them progress in the missions was ... futile.

There are no aspects of the game that require you to do anything of the sort, nor is there any point in the game where a purchase is mandatory. You're certainly incentivised to buy stuff, at times heavily so, but you're never required to do so. I personally am a 100% FTP player, and feel I'm quite far into end-game, and have never felt that I couldn't progress because of my lack of appetite to spend money.

I'd imagine it was more the technical aspect of how they would even verify that you actually shared the referral link with anyone. 

Thanks all.

My takeaway here is - all that is required to complete the "Referral Link" Mission is just to click on the Referral Link (which posts the link to clipbaord). You do NOT have to send the link to anyone, nor do they have to download and run the game in order for you to get credit for that Mission.

Once again, Thanks all!