Zillow.com boasted in a blog post earlier this week that it was the most visited real estate Web site in the country during the month of November -- citing statistics from comScore that it had surpassed industry giant Realtor.com.

We thought the milestone was pretty significant for the Seattle startup, so we reported on it. But, as it turns out, it wasn't true and Zillow still trails Realtor.com in the numbers game.

"After discussions with comScore, it appears that the comScore data we cite below may be unreliable and it includes a different approach to Zillow’s measurement than other sites," said Zillow spokeswoman Amy Bohutinksy in an update to her blog post "Zillow's Spectacular November."

Bohutinksy then refers reader to this detailed post from Inman News which explains what went wrong. (Inman, like TechFlash, picked up on the original Zillow blog post).

So, what led to the snafu? Apparently, Zillow based its blog post on a report that had not yet been made public. As a result, Zillow published numbers for other real estate companies that had not taken into account a new methodology being employed by comScore.

Because of that, Zillow's numbers appeared to be higher than some of the other sites. In fact, Zillow -- which according to comScore showed 3.013 million unique visitors for November -- trailed Realtor.com, Yahoo Real Estate and AOL Real Estate.

Here's more from Inman on the mess:

When Inman News first contacted comScore about Zillow's claim, comScore initially provided a table that also mixed "panel only" data for top real estate sites with "hybrid methodology" numbers for Zillow.com -- the very practice it advises clients not to engage in. After Radwanick was asked if those numbers provided an "apples to apples" comparison, she provided another table listing only the "panel based" numbers, which showed Zillow with 3 million unique visitors in November instead of 5.2 million. The unique visitor count is supposed to count each person who visits a site once, no matter how many times they return to a site in a given time period.

Bohutinksy, who heads PR for Zillow, was miffed by the entire episode. She told TechFlash this morning that the company did not receive word from comScore about the change in data until after the blog post was published.

"If this sounds confusing to you, trust us — it is to us too," she said in a statement. "We will certainly think twice about publishing comScore data moving forward."