[ronancremin]

Yes.

The user agent (UA) string is used by almost every major web brand for one or more of the following purposes:

- To serve different levels of experience to different classes of browsers. This is necessary if you want global coverage i.e. all classes of devices and connectivity. The payload of desktop version of Google is fully 140x bigger than the lightest mobile version, Facebook is similar (check this on http://prism.mobiforge.com). RWD can't do this (many RWD sites simply don't load at all on lower-end phones).

- Serving different experiences to different types of devices e.g. desktop / mobile / TV etc. Don't think this is necessary? Try some of the sites mentioned with a different UA strong and see how it feels.

- Analytics. Google Analytics, Omniture etc. all rely on the UA string to identify types of devices/browser.

- To offer links to the correct app stores for the various mobile OSes

- To make sites faster/lighter for lower end devices. This is important for low-speed connections, faster page loads, metered data plans.

[gnur]

Ah good point. But what I really meant, and that isn't really clear from my post: Is wether we still need the addition crap that is in a user agent string. A user agent should be more like this: <Operating System> <version>, <browser> <version>, <devicetype>, <connection type>(high speed unmetered, 3g metered etc)