Buying online is convenient. And now almost everybody does it: Placing orders using a computer has grown to the point where, according to Internet market research company, more than seven out of 10 Internet users now shop online.

But homeowners aren't likely to buy a roofing or siding job via the Internet because someone knowledgeable still has to estimate the job, factoring in potential problems and their expense, to arrive at a price that reflects actual job costs.

Online window sales, on the other hand, are growing. The mystery of what windows cost remained intact until low-price sellers gained a foothold in the market with the famous $189 window, which became a benchmark.

There are companies that have been selling windows online for 10 years. These businesses used to be an anomaly, but now even large traditional window companies are considering selling their product online in some form.

Why? Because there are homeowners who want to buy this way. Part of it is habit: Consumers have gotten used to online shopping, including buying products that they wouldn't have considered buying via the Internet five or 10 years ago. The other part is caution. The recession changed the way that many people think about spending money. They're more careful, and careful includes knowing what something costs before committing to buying.

Here are some thoughts on Internet window sales. It's unlikely that a large portion of window replacement jobs will be transacted as online business. Consumers will continue to use the Web to educate themselves about companies and products, but they're still going to want to meet with someone in person to look at their home and make recommendations because the cost of making a mistake outweighs the savings that might result from buying cheaply without a visit from anyone but the installer.

On the other hand, homeowners are going to feel increasingly entitled to an up-front price. So insisting that that's not possible because every house is different may no longer be a convincing argument.

But, you're thinking, these consumers are just price shoppers. To which I say: These days, who isn't? The key to winning their business may well be the degree to which you can convince them that your company will make doing business fast, painless, and pressure-free. If they have to pay more for that, many, if not most, will.

Jim Cory, Editor