If your LTV > CAC then yes. LTV = Lifetime Value of your customer CAC = the customer acqusition cost Since the CPC on AdWords are quite high and finally the

If your LTV > CAC then yes. LTV = Lifetime Value of your customer CAC = the customer acqusition cost Since the CPC on AdWords are quite high and finally the resulting CAC will be also quite high (still depends on your conversion) you need a product with a high LTV. I don't know how much LTV you try to achieve with HackerEarth but it should above be $100. Cheaper channels: affiliate (so CPA based deals) or SEO