Tell us where you are! Adding locators to addresses
I suspect many advertisers and ad designers don't really think about this - in a print ad they just put in their address (sometimes even with a zip code).
Important: an address often doesn't clearly convey where a business is located.

Memorial is a really long street with miles of commercial establishments. The address 3330 doesn't help at all. It is actually between Lake Hefner Parkway and May Avenue, two very major landmark streets in north OKC. There is room in the ad to tell us that.

This new restaurant (therefore, their target audience is new customers) is on Boulevard, just south of Memorial. Technically, the street name changes to Eastern right in there, but most people would recognize Boulevard.

Somewhere on Interstate 240? Not very helpful. Its just west of Western. That's better.
North Glenstone? This ad was in a tourist guide - directed to people who do not know the streets of Springfield.

A more respectful and clearer way
When you tell someone your home address, don't you usually provide a clearer descriptor:
"424 East 4th", "Between University and Main, just south of 2nd Street."

So, simply do the very same for a business:

Adding a map is a great idea - the reader can better visualize a location.

"Off 2nd & Bryant, west side of Super Target" can't be much clearer. Nice.

Avanti gives us plenty of info - good for them. Beef gives us the major locator intersections.

The Kamber's ad doesn't even have a postal address - just the intersection. The kids ad even tells us which corner - the northwest.

Let major stores serve as landmarks.

This August 2011 ad for Integris Health includes both a text explanation and a map. Very nice.

Design from the POV of the user
The regular user probly doesn't need a complete address, maybe just a reminder. But infrequent and new customers need more info. Be considerate and empathetic of your customer. It is rude to ask a customer to work harder at finding you - check the web, a map, or a phone call? Just provide the info they want/need.
Lesson: create, critique, proofread, edit your work through the eyes of the user.
Tip: Don't just put a postal address in your ad and think that's enough. Provide landmark descriptors.