I haven't used Appen platform at all but they must have done...

I haven't used Appen platform at all but they must have done something right. The concept of crowdsourcing has been around for long time. Amazon started Mechanical Turk in 2005, but barely anyone knows what it is. It is essentially Appen but it doesn't get much traction. Amazon tries to get back into that market again with Amazon SageMaker Ground Truth - Appen's figure 8 equivalent. Appen and Amazon are the only 2 strong players on the market that i am aware. However none of the large tech companies trusts Amazon, this is probably why Appen has a larger network and get the job from the top tier companies. The demand for this service will be around for long time. Yes at some point, it will trend down, but i think it will be in good shape in the next 5 years. I'm much comfortable holding this than Afterpay for example