Although I've had several calls about Drobo recoveries over the years, I've yet to find anyone who thinks their data is worth our minor data recovery rates to send one in. As most Drobo users are using the unit because they don't value their data enough to get a real RAID or NAS, it seems reasonable that they are going to be equally cheap when it comes to data recovery services.
I think the same goes for ZFS. The most common place for it, that I know of, is FreeNAS systems where the owner puts their critical data on the cheapest hardware possible.