If today you feel the urge to shop online, you are not alone. Forrester Research predicts holiday online retail sales of $27 billion with today (the first Monday after Thanksgiving) and next Monday reputed to be the busiest days of the year for Internet shopping. These days are variously known as Black Monday, e-Day, and other names suggestive of online shopping.

As the story goes, millions of us return to work today and purchase online some of the items we failed to find in shopping malls over the weekend. But in reality, we Americans shop online much more than either our government or even many industry experts imagine.

If your boss catches you shopping online, just explain that, as federal statistics reveal, online shopping is mostly for wholesale and business-related activities rather than personal retail shopping. Don’t explain further that the federal data are likely gross underestimates of online retail shopping.

According to the Census Bureau, the most intensive online sectors of the economy are manufacturing (23.4% of shipments) and merchant wholesaling (17.2% of sales). Many office workers spend their days buying and selling goods and services online on behalf of their employer.

Retail sales and other consumer services are in the low single-digit shares according to the Census Bureau. It recently announced that third quarter electronic commerce retail sales exceeded $25 billion, or little more than 2.6% of total retail sales. For all of 2006, the Census Bureau expects these retail sales to exceed $100 billion.

Although those figures reflect a more than 20% increase from last year, they are still underwhelming. They suggest that more than 97% of retail sales in America are not online. Online sales, or so the numbers suggest, are only a small specialized segment of retail trade.

But the Census Bureau retail numbers reflect only a part — perhaps not even the largest part — of online retail sales in the United States. Much of retail commerce is not officially counted as e-commerce by the Census Bureau. Only retail establishments that record online sales separately are counted, and many retail establishments do not keep such records. For example, much of the tens of billions of dollars in retail sales to small retail outlets, including eBay vendors, are not recorded by the Census Bureau as electronic commerce at all.

Other retail sales are substantially conducted online except for the final transaction. For example, many consumers choose and survey products from houses to automobiles to major appliances to consumer electronics online but make the final purchase in person. The Web site Craigslist.com has significantly displaced classified advertisements in metropolitan-area newspapers for many services and second-hand products.

These and other retail transactions are not recorded as electronic commerce, but the transactions would not have taken place as efficiently, if at all, but for the Internet. Whether at home or at the office, we Americans use the Internet to search for goods and services that are not formally purchased online. Shopping online brings us every conceivable retail outlet in the world rather than the few that we can physically reach in an hour.

Still other online transactions are not recorded as “retail” at all, and many of these online services appear to be understated. For example, airline tickets and tickets for entertainment and sporting events are recorded in nonretail categories. According to the latest (2004) Census Bureau information for airline tickets, only 22% of travel services and reservation arrangements were made online. Many Americans would be surprised that 78% of such reservations are not made online.

Advertisers know far more than the government does about our Internet usage. The Interactive Advertising Bureau and PriceWaterhouseCoopers LLP estimate Internet advertising at $4.2 billion in the third quarter, up more than 30% from one year ago, or a much more rapid rate of growth than the 20% estimated by the Census Bureau. Total Internet advertising for 2006 will represent far more than the 3% share of retail sales that the Census Bureau attributes to the Internet.

On Black Friday, television cameras portrayed Americans eagerly waiting in line for shopping malls to open at midnight. But most Americans were not at shopping malls; we were home soundly asleep, or perhaps shopping online.

A former FCC commissioner, Mr. Furchtgott-Roth is president of Furchtgott-Roth Economic Enterprises. He can be reached at hfr@furchtgott-roth.com.