I recently attended a conference on locative media and the definition of locative media offered, and one that is often assumed, is that locative media are mediums that address a physical space through digital technology.
It is safe to assume there is consensus that locative media, should be media that address the location issue. But I find the digital assumption to be problematic. It may be useful for writers and pundits to use the term to distinguish it as a trend or as emerging technology, as per the use of term social media.
I think digital is not a defining traits so much as the ability to (easily) access a medium's content while in the referenced space.
Films, for example, would not generally be locative if viewed on a screen or television. So Herzog's Cave of Forgotten Dreams about the cave paintings in southern France are not locative. But it could be, if it was viewed on a mobile device or laptop while at the cave (or the cave authorities have a screening room at their interpretation centre). It's more feasible to consider a scenario of watching a clip of Woody Allen's Manhattan on a tablet while sitting in Central Park.
Access to the medium is definitely a defining trait too. Books about a place are not often easily accessible while at a given location unless one has planned ahead and brought the book along (as happens with travel guides). But this access barrier is breaking down with the growing popularity of e-books (although the form of the medium, i.e. its length, makes it less suitable for place-based consumption).
So if many media have locative aspects, perhaps the term locative media is meant for media that are exclusively locative, that is primarily consumed while at a location? This would be the case for interactive kiosks that malls and museums often use for wayfinding and other place-related information. Digital media don't have a monopoly on locative however, as plaques and print guestbooks, for examples, are non-digital and exclusively locative. The idea of exclusivity is problematic as some media may be mostly used while at a location, for example travel guidebooks or geosocial networking apps, can be also used a lot while in various locations.
I'm thinking that a definition of locative media would then be media that address place and are used while in the place.
I think discussing what the term locative media means is important not just for researchers and scholars in the field, but for developers and content creators. Considering the prior media that have come before and offer their strengths and weaknesses can be invaluable for guiding design and technical decisions.