Just a few weeks ago, I did a blog entry looking at why it's hard being green. Most people will recycle but they'll refuse to change lifestyles to reduce climate change. So what are the lessons for green businesses?

Research out of Stanford Graduate School of Business suggests that companies will need to reassess their marketing and sales strategies to sell green products.

To begin with, the researchers say companies will need to provide consumers with incentives to buy the goods and services. These incentives can be positive, like the benefits you might get buying the item, or negative, like the impact it might have if you don't.

Just as importantly, they say the products and services need champions, people who can talk to the mainstream market to make sure people buy.

The other issue is that most consumers don't like paying more for green products, something that's a problem given the fact that most green products are sold as premium products. The only reason they might pay extra would be if it does something for their identity like, for example, buying a Prius. And just as most consumers won't pay more for green products, they won't choose products that don't work as well as the alternatives. Indeed, the products would have to work better than the alternatives.

All this raises a number of questions for businesses. Should stores have positive incentive like faster check out lines for green products? Or should they have negative incentives like a slower line for those who need plastic bags? And if companies provide rebates for shoppers, how much should they pay to make it worth the while of the consumer?

Over the next two to three years, many more companies will be asking themselves these questions.