WebProNews mentioned today that Google signed an agreement with Clear Channel, which is the "largest radio station group owner in the U.S."  [more info] This has been mentioned before, but I haven't really payed a lot of attention to it.

I've been of the mind that Google Ads have mostly been effective because they're so transparent and  streamlined with search results.  When I initially heard about Audio Ads, I figured there'd be little "Play Now" buttons in the SERPs instead of textual advertising.  I tuned the subject out of that, as I wasn't interested.  Ooops.

The ability to push radio ads is actually really good.  Usually this can be very expensive.  With Google having reserved a "portion of guaranteed, premium 30-second advertising inventory on 675 Clear Channel AM  and FM stations", I imagine they'll be very cost-effective.

Google Audio Ads are still in Beta (of course!) but the demo presentation is well worth watching.  It shows off a lot of great features, and also gives an idea of costing.  In the example, they've bid $3 per thousand listeners.  Which isn't too bad at all!  (The weekly budget was $500).  The estimate in the demo showed 400,000 impressions, at $8 CPM, with a total cost of $1,203.  (Thats for 2 campaigns, not exceeding $500 per-week)

You can get specific with your schedule too, choosing days and timeslots and target markets. Demographics seem to be mostly decided by music-style. Thats not perfect as such – it’d be nice to be able to choose by age group, income (disposable and net), and so forth – but I think thats pretty decent for radio. You can also choose by location – so target specific ZIP codes or states.

There's the ability to "reserve" vs "auction" ads too.  Reserve means you reserve ad-space in advance, ensuring your ads get played.  Its more expensive, but could be useful for time-sensitive offers and promotions.

Call Reporting is a nice feature.  One nice thing about Adwords is the ability to track conversions.  This works on clicks, which obviously does not apply to listeners.  Call Reporting works by supplying another number.  Anybody who calls that number gets bounced to your regular number, but Google will log details like time of call, location call originated from, and so forth.  (This feature only available to US numbers)

From the 'learn more' section:

Create a custom radio ad. Creating a radio ad that's customized for your business is easy with our Ad Creation Marketplace, through which you can find professionals who can provide quality script, editing, production and voice-over talent - all on your budget.

Its not clear as to whether or not you can upload an audio file of a pre-recorded advertisement.

I'm pretty impressed with this offering.  Depending on how expensive it really is, this could be an excellent way to boost sales in a lot of markets.

Unfortunately, the Audio Ads service is only available to US customers at this time.  As I said, its still in beta - so hopefully they'll open it up to the global market in a couple months time.