Backpack services provide tools to enable you to push your badges to publicly accessible webpages. However it is also anticipated that other sites will want to display these credentials (badges) or, more importantly, learners will want social networking sites, blogs etc to provide functionality so they can display their badges.
The strategy here can be either :
Of the two both would happen but the preferred option is obviously the second because it involves a process to verify that the badges have been legitimately earned.
However, although it sounds reasonable the technical framework to support this is currently primitive. A displayer API1 is currently in development but by no means usable at present.
The intention is that badges themselves have all the information required to verify a badge but at this moment it seems (there is conflicting information on the documentation about this) this is not encouraged because there is no failsafe way to ensure that this embedded information is legitimate either.
So for the meantime while the OpenBadges site does claim there is a simple way to be a 'displayer' - "The OBI is open and supports any independent displayer that conforms to the necessary displaying specifications."2 this is incorrect at present.
That is not necessarily negative since the OpenBadges project is working to fill these gaps and the other elements of the ecosystem mean that badges can be earned, issued and displayed even though the displaying process is not yet optimal. In time it seems this will be resolved too.