[Arnavion]

- It works for every application on your computer, not just web browsers that also support adblocking addons. Useful for applications with embedded web browsers (game clients, chat clients, etc).

- The failure mode is to block rather than allow. Even with a browser with adblocking addons, the addon could accidentally be disabled or uninstalled (by you, by a browser bug, by a browser feature, etc), so you'll start seeing ads. If the DNS server gets disabled you won't be able to resolve anything, let alone see ads.

(I used to do a home-made version of this, but resolving to a local gifserv so that I didn't have to see "page could not load" errors from ad spaces. But recently I got a pfsense router so I've switched to pfblockerng instead.)