Blitzkrieg IPO or the next Worldcom?

I am aware that most of you guys across the Atlantic are more interested in the likes of Alibaba, but here in Europe RocketInternet and Zalando have split the market into two groups: Rocket cultists who see RI and Zalando as the most sucessful upcoming European IPOs ever, which will eventually evolve into European stock behemoths and the naysayers (like me) who believe RI and Zalando, two intransperant companies who feed on the ideas of other people, will crash and burn and bring about the next big market correction.

I would like to know if any of you have RI and/or Zalando on their radar and would partake in an upcoming IPO. Also, do you think the new German trend of copying innovative US tech-business concepts, rolling them out globally and ultimately selling the clone back to the idea generator is morally sound? What impact do such practices have on the innovativeness of the largest European economy and its future potential?