I guess to be more detailed I have redundant connection to the internet. Each of these I am exporting my OSPF routes to. Since all routes are equal across OSPF, they are advertised equally through BGP regardless of the location should be prioritized as the best path.
So if I have an interconnected network using OSPF to propagate my internal routes. I then take those internal routes and want to send all internal routes to all DIA circuits for redundancy. If I have a location in LA another in Denver and another in Dallas I do not want traffic destined to a location in Dallas to prefer to come on the Denver DIA.
I was thinking this should be done from the internal OSPF routes, but after reconsidering I think it have to do with both OSPF preferences internally and also BGP advertisements.