The benefit is that Arturia doesn't need to give away software for free in exchange because the reviewer already own it. It's surely less expensive for them..
In any case: This deal was a very lame decision from Arturia in my eyes. I must say i'm a bit disappointed that a company like Arturia act that stupid. We see what happened here: The guy hardly found time to use it and wrote a review because his license gonna expire. So we have a laughable review not worth to mention and a thread where Arturia customers suddenly see this company in another light. At least i do.

