Video quality evaluation with subjective testing is both time consuming and expensive. A promising new approach to traditional testing is the so-called crowdsourcing, moving the testing effort into the Internet. The advantages of this approach are not only the access to a larger and more diverse pool of test subjects, but also the significant reduction of the financial burden. Recent contributions have also shown that crowd-based video quality assessment can deliver results comparable to traditional testing in some cases. In general, however, new problems arise, as no longer every test detail can be controlled, resulting in less reliable results. Therefore we will discuss in this contribution the conceptual, technical, motivational and reliability challenges that need to be addressed, before this promising approach to subjective testing can become a valid alternative to the testing in standardized environments.