I was feeling extra perky this morning until I got to the office and read that e-commerce is now a full decade old.

That means that your teenager can hardly remember a world when you couldn’t go online and order groceries or buy something fleecy over the Net from Land’s End or download the latest hot music track.

Man, do I feel old. I remember DOS, Lotus 1-2-3 and Ashton-Tate.

I find myself starting sentences with “back in day.” Then, I kick myself, fire up some Interpol or Queens of the Stone Age on the iPod and say, “shut up, grandma!” Just because I remember the old days, it doesn’t mean I want them back - with the exception of XyWrite and Kozmo.com.

Then, I remember that I’m not old (well, not that old) or averse to change; I’m just cynical and cranky. Actually, I’m usually the first one of friends to embrace most new technologies. I have an iPod, a Blackberry, a digital camera, a cell phone with camera built-in, TiVO, three different video gaming systems and so many other gadgets it’s almost embarrassing.

At my power strip/surge protector overloaded household we have multiple DSL lines, a half dozen PCs and laptops, wireless networking and more mass storage capacity than NASA.The list of what I’d be willing to give up before losing my broadband Internet connection is extremely long.

There must be a lot of others who feel the same way. A new report from eMarketer says that e-commerce is now a $140 billion business. Count me in for a hefty portion of that. I do all my banking and bill paying online. I order something over the Internet at least two times a week (my husband and VISA will attest that that). Whether it’s Omaha steaks, shoes, clothing, makeup, books, or gifts for my family and friends, I spend a huge amount of time making online purchases. Over the last decade I’ve seen the UPS and FedEx guys (hi Dave and Marco) more than some members of my far-flung family.

And now it looks like the rest of consumers are catching up with me. According to the eMarketer report, the demographic profile of the online shopper has evolved since the early days of online shopping. “In its infancy online shopping was the purview of well-educated, high-earning, 20- and 30-year old single, white males. Today online shoppers closely resemble the US population as a whole,” says Jeffrey Grau, eMarketer Senior Analyst and author of the report.

The e-commerce landscape is also evolving. It’s no longer the domain of Internet-only retailers. It’s currently a mix of online and traditional brick-and-mortar retailers. One key piece of evidence that consumers are becoming savvier about shopping online is that comparison-shopping sites, such as Shopping.com, Yahoo! Shopping and Shopzilla, are also consistently showing up among the top retail Web properties.

So, Happy Birthday E-Commerce. You’ve come a long way, baby since the days of the Pets.com Sock Puppet and Webvan.com.

I’d break into a rousing rendition of Happy Birthday in honor of the e-commerce milestone, but then I’d owe someone royalties. Those privileged few (I can count you on one hand) that have actually heard me attempt a tune can thank me later for not singing.

Let me know about your ecommerce milestones.