Anyone on the hunt for a home knows how tough the competition has gotten in metro Atlanta. Homes in coveted areas can spark bidding wars in a just a short period of time. So the more options you have available to you when you are searching listings the better.

A new ad campaign from Realtor.com  raised an important question about the data we get from listings services.

Realtor.com has wrapped a for-sale house in Austin in black paper to demonstrate how you may miss your dream home if you search Zillow listings instead of Realtor.com.

This "experiential advertising" is based on Realtor.com's internal analysis showing that about 20 percent or 300,000 more MLS-listed for sale homes nationwide appear on their website compared to Zillow's. In some markets, the gap is more than 100 percent, they claim. Here are the cities with listings gaps:

Austin: 33 percent

Denver: 30 percent

Memphis: 42 percent

Miami: 52 percent

New Orleans: 67 percent

Salt Lake City: 109 percent

San Diego: 48 percent

That seems pretty dramatic, particularly in Salt Lake City, but the claim may or may not hold up when you dig deeper.

Multiple Listing Service (MLS)  is where all agents and brokers enter active listings. Then services like Zillow and Realtor.com pull from there. What shows up in either service depends on the listings they choose to pull and whether one website has more listings than the other depends on what they classify as listings.

"Are they comparing active to active listings or does one site have active, under-contract, pending and sold as part of their listings?" said Karen Cannon, owner of Karen Cannon Realtors.  "If someone wants to challenge them on it, they have to provide the criteria for their data."

Cannon has seen just how fast things are moving these days. Her company focuses on some of the most competitive neighborhoods in the metro area -- Dunwoody, Sandy Springs and North Atlanta.

RELATED: Dunwoody tops list for costly housing market; Riverdale most affordable

She has had buyers call to inquire about a listing they found on Zillow, only to discover the home is under contract.

"There is so much access out there for buyers today and they are much more internet savvy and knowledgeable about the marketplace," she said.

Rather than worry about which service they use to search, the most important thing buyers can do is make sure they have correctly set up their search to pull active listings from their desired area. Buyers need to know as soon as something hits the market, not a day later, Cannon said, so setting up the correct search -- or having an agent do it for you -- is vital.

Another issue for buyers in this competitive market is navigating multiple bids that may come in on a single home. Figuring out how to compete and have a winning offer requires flexibility and a in-the-know realtor.

In addition to traditional strategies such as pre-approvals and contingencies, there are some other less-common methods to winning an offer.

It isn't unheard of for buyers to send personal notes and pictures as part of their offers on homes with multiple buyers. Cannon recently had a case where her client had five offers on their house. Several buyers submitted personal notes, pictures and other incentives to the seller. Her client ultimately accepted an offer that was not only financially competitive, but came from one of the buyers who went the extra mile.