A referral invite system has proven to be a useful tool to acquire new users or customers in a cost-efficient way.
We have examples such as Guild of Guardians (GoG) where more than 50% of their sales come from referral links being used. Another example is Wonderverse. They give you 10 of their fungible tokens (cryptocurrency) by joining their discord server and additional 10 for each referral you have invited to earn up to 150 tokens more.
I have personally experienced the above examples and seen the massive growth of both; GoG >50K Discord members and >$10M in sales, Wonderverse >12K Discord members in less than a month.
It is true that there is a risk of getting a lot of user who won't engage with your product. But we also see a lot of good reasons why to use this type of carrot stick.
Using tokens as a reward allows you to cost-effectively attract and educate users. The more educated they become the more likely they are to stick and use your product or contribute to your community. This is why, we see examples like the biggest crypto exchange in the U.S, Coinbase, who had acquired Earn.com. With Earn, Coinbase has created an academy platform where one can learn about different crypto projects and receive $10 of the projects tokens by watching tutorials and doing quizzes. I have a friend who did this and 4-5 months afterwards his tokens went from being worth $10 to $400. That's a pretty good pay from just watching a 10-min tutorial and do a quiz.
You might wonder if you need to learn how to write smart contracts in order to build a Dapp that has fungible tokens and a referral system to reward users with the tokens. This is no longer necessary, as we have marketplaces for smart contracts like the Hyperverse.
Hyperverse has composable smart modules such as fungible token modules that allow you to create, mint and transfer tokens. The modules have been audited and deployed on blockchains such as Ethereum, Algorand, and Flow. This means developers get to focus on what they are good at, which is building apps, and won't have to worry about the integration of crypto wallets or writing smart contract code.