zillow3.gifReal estate Web site Zillow.com continues to show momentum.

The Seattle company has released a new feature called Home Q&A, letting people ask questions and get answers about each of more than 70 million U.S. homes. Zillow demonstrated the feature to VentureBeat two weeks ago. If Zillow can leverage the traffic it is getting from its controversial home price estimates — and signs are that its traffic is robust and growing (see Hitwise rankings in spreadsheet below) — and thereby get enough people to make these Q&As lively, it could be a breakthrough feature.

This appears to be a swift competitive response to My Currency, a younger company that relies on user-generated commentary about home prices, and which needs a new URL if anyone is going to find it.

If you’re a home buyer and see a quirky listing — the house may have been listed for a long time, whatever — you can ask a question about the house and get feedback (hopefully, people will respond; agents will have the most reason to do so, because they know the most, and because their comments will include a link back to their own profile page at Zillow, so that they can get leads.)

If you’re curious about the neighborhood or commute patterns, you can ask about these too. Zillow has introduced a host of other features around this. You can load historical photos of the homes, for example. Anyone can rate answers as “helpful” or “not helpful,” and Zillow has hired people to troll the site to remove spam from agents or others. (See screenshot below).

The feature follows Zillow’s move to enabled homeowners and agents to update home facts, and post homes for sale. There’s also a notable “Make Me Move” feature, where an owner who is not otherwise interested in selling can list the price of an offer so enticing that they couldn’t resist taking it anyway.

Zillow has also introduced an advertising feature, which lets agents, professionals and others take out geographically targeted ads, which get listed on pages people get when they search for homes on Zillow.

The year-old Zillow says it attracted more than four million unique visitors in February.