In Facebook’s latest monthly Facebook Ads Newsletter, it announced that advertisers now have the option to include or exclude existing fans of their Page, users of their app, or attendees of their Event in ads targeted to “Friends of Connections” — friends of existing fans, users, or attendees. Previously, those already connected to an advertiser’s Facebook property were automatically excluded.

The change allows advertisers to gain new connections and re-engage their existing connections with a single ad, or specifically target ads to those who are connected and have friends who are connected as well. The change has been applied retroactively, so any ongoing Friends of Connections ad campaigns will now appear to existing connections unless they’re explicitly excluded.

Launched in November 2009, Friends of Connections ads show social context, or the names of a viewer’s friends who are already connected to the Facebook Page, app, or Event being advertised. This social context creates an implicit recommendation for the ad’s destination by a friend, increasing trust and click-through rates.

Now the “Connections on Facebook” targeting section of the ads creator shows a check box to activate Friends of Connections targeting for the destination of the ad. Radio buttons allow advertisers to refine Friends of Connections targeting to “Anyone” — connections and non-connections alike, only people who are connected, or only people who are not connected.

Advertisers can click the “Advanced connection targeting” button to reveal options to include or exclude connections to other Facebook properties they control.

In some cases, advertisers may only be seeking to generate new connections  not re-engage existing connections. They would then want to check the Friends of Connections box, and set their radio button to “Only people who are not fans/using/attending”. Meanwhile, apps or Pages that depend on network effect can now choose to only target existing connections with friends that are connected too.