In Fandango, LLC v, Ameranth, Inc., CBM2014-00013 Paper 22 (March 24, 2014), Apple learned the hardway the downside of filing a joint petitioner for covered busness method review:  The Board will only a permit single representation.  This not only restricts the choice of counsel, but it affects the choice of arguments. The joint parties cannot take different, let alone inconsistent positions, because they are one petitioner, represented by a single counsel.  While you save on filing fees, you lose on the ability to control the arguments presented.  Joint Petitioners should think carefully about marriage (and probably have a iron-clad pre-nup).