Local.com yesterday announced an ad distribution deal with Hearst-owned White Directory Publishers. The deal will bring Local.com’s display ad inventory to White’s national sales force.

In this way it presents an opportunity for White to appeal to national advertisers that want to target locally. Local targeting will happens through Local.com’s geographically relevant traffic sources — both its content network of local sites, and searches that happen on Local.com proper.

This should resonate most among national advertisers with many locations such as restaurants, retail and to some extent auto manufacturers. Local.com is a big source of local traffic, whose value will increase if national advertisers realize that local targeting for display ads can go beyond the demographic targeting they get from most ad networks.

Other sources of local traffic include Topix and Marchex (OpenList). The latter recently repackaged its local advertising for this very reason — to make local targeting more appealing and digestible to national advertisers.

The next step will be to tie display ad units to some form of directional media capacity to telescope into store locators (possibly utilizing location awareness), local maps, or even local inventory data. These things are all being developed separately but could come together to create powerful local advertising mashups.