Zillow CEO Spencer Rascoff (center, above "Z"), joined by other company executives, rang the opening bell for the Nasdaq today to celebrate the company's initial public offering.

Five years after shaking up the real estate industry by making public property records and automated home valuations available to consumers online, Zillow Inc. today became a publicly traded company valued at nearly $1 billion.

Zillow said it raised $75.7 million in the IPO and private placement of 3.7 million shares priced at $20 each. Investors promptly bid the shares up to more than double that price after trading commenced this morning on the Nasdaq.

By early afternoon, Zillow's share price had settled down into the $35 range -- which would put the company's market capitalization at about $962 million, if underwriters exercise an over-allotment option to bring shares outstanding to a total of 27.5 million in coming weeks.

On the heels of Google’s blow-out Q2 2011 earnings announcement last week, we wanted to find out what keywords demand the highest costs per click and are most competitive in terms of high search volume. Since the vast majority of Google's profits come from AdWords advertising, these high CPC keyword categories are responsible for a large part of Google's profits. The results of our research are illustrated in an infographic of the most expensive keywords. (Click the image to enlarge.)

The 20 keyword categories with the highest search volume and highest costs per click, thereby netting Google the most money, are:

1. Insurance (example keywords in this category include "buy car insurance online" and "auto insurance price quotes")
2. Loans (example keywords include "consolidate graduate student loans" and "cheapest homeowner loans")
3. Mortgage (example keywords include “refinanced second mortgages” and “remortgage with bad credit”)
4. Attorney (example keywords include “personal injury attorney” and “dui defense attorney”)
5. Credit (example keywords include “home equity line of credit” and “bad credit home buyer”)
6. Lawyer ("personal  injury lawyer," "criminal defense lawyer)
7. Donate ("car donation centers," "donating a used car")
8. Degree ("criminal justice degrees online," "psychology bachelors degree online")
9. Hosting ("hosting ms exchange," "managed web hosting solution")
10. Claim ("personal injury claim," "accident claims no win no fee")
11. Conference Call ("best conference call service," "conference calls toll free")
12. Trading ("cheap online trading," "stock trades online")
13. Software ("crm software programs," "help desk software cheap")
14. Recovery ("raid server data recovery," "hard drive recovery laptop")
15. Transfer ("zero apr balance transfer," "credit card balance transfer zero interest")
16. Gas/Electricity ("business electricity price comparison," "switch gas and electricity suppliers")
17. Classes ("criminal justice online classes," "online classes business administration")
18. Rehab ("alcohol rehab centers," "crack rehab centers")
19. Treatment ("mesothelioma treatment options," "drug treatment centers")
20. Cord Blood ("cordblood bank," "store umbilical cord blood")

We found that that 97% of Google's revenue comes from advertising on Google sites. In the last four quarters alone (Q3 2010-Q2 2011), Google brought in $32.2 billion in total advertising revenue.

Google AdWords is a dynamic, auction-based marketplace where advertisers bid on keywords to compete for top ad placement. The minimum bid per keyword is 5 cents, but this research shows that in highly competitive categories, Google can make up to $50 per click. Despite a diversified product portfolio, advertising on Google sites accounts for the vast majority of its billions in annual revenue.

The keyword categories with the highest volumes and costs represent businesses with very high lifetime customer value – in other words, these industries can afford to pay a lot to acquire a new customer. These businesses include lawsuits, mortgage applications, and server hosting. Some high-volume keyword categories have lower CPCs because advertisers have slimmer margins to expend on PPC advertising.

No real estate advertising keywords. I believe that Google makes 97% of its revenue from advertising (Android is apparently not that much of a cash cow), but I'm slightly dubious that the majority of all ads pertain to insurance and that "cord blood" is a top keyword compared to the adult industry...

Realtor.com operator Move Inc. has acquired social media search platform SocialBios, and the company's three co-founders have joined Move's product development team.

Move said SocialBios -- named "Best Tech Startup" in January by attendees at Inman Connect New York City -- will continue to be based in Denver, Colo., and that its products and brand will remain in production and available to real estate professionals. Terms of the deal were not disclosed.

SocialBios says its "social layering" technology helps real estate brokerages and other businesses turn their websites' "About us" pages into social networking hubs by allowing visitors to see how they are already connected to agents through Facebook, Twitter, Foursquare, Gmail, and LinkedIn.

Most entrepreneurs think about the color of their site in terms of how colors look together and whether they’re generally appealing, but color actually has a lot more to do with what your visitors think about your site – and the actions they take – than you might realize.

There have been entire books written about the psychology of color in buying habits. It’s a topic that has been well studied, and most marketing degrees include at least some study of this topic. We don’t want to bore you with psychology talk though. So here are the basics of what various colors mean, who they appeal to, and who should use them.

First, a Few Stats

Some of these statistics have to do with the color of individual products, but they demonstrate very clearly the power color has in the minds of consumers. According to a recent KISSMetrics report:

• 93% of consumers place color and appearance above other factors when making a buying decision.

• 85% of shoppers state color as the primary factor in their decision to buy a product.

• Brand recognition, which links directly to consumer confidence, is increased by 80% when the right colors are used.

What Does it Mean?

It’s important to know what specific colors mean to people. It’s been shown that certain colors invoke specific feelings in most people, so let’s see what colors really mean.

Yellow: Youthful and optimistic. Use it to grab attention. Usually not good as a background or primary site color.

Red: Energy. Creates urgency and increases heart rate. Good for appealing to impulse shoppers.

Blue: Creates feelings of trust and security. This is why many banks use it in their logos or marketing. Navy or dark blue  is used to market to the budget-conscious.

Green: Gives the impression of wealth. Relaxing and easy-going. Teal can be used to appeal to people on a budget.

Orange: Aggressive and excitement. Good for calls to action and impulse buying.

Pink: Feminine and romantic. Used to market to women and girls and traditional buyers.

Black: Powerful and sleek. Use it to market luxury products and appeal to impulse buyers.\

Purple: Soothing and calming. Often used to market anti-aging products.

Part of the study mentioned above found that what your site visitors see when they come to your site, from overall design to the colors used, really does make an impact on whether they buy from you. In fact, 52% of people surveyed who said they would not return to a site stated the reason as ‘aesthetics.’ If there was ever any question, that should confirm that the look of your site is one of the most important parts of your business.

If you're like most people I work with in companies, the demands come at you from every angle, all day long, and you have to make difficult decisions without much time to think about them. What enduring principles can you rely on to make choices that reflect openness, integrity and authenticity?

Here are ten that work for me:

1. Always challenge certainty, especially your own. When you think you're undeniably right, ask yourself "What might I be missing here?" If we could truly figure it all out, what else would there be left to do?

2. Excellence is an unrelenting struggle, but it's also the surest route to enduring satisfaction. Amy Chua , the over-the-top "Tiger Mother," was right that there's no shortcut to excellence. Getting there requires practicing deliberately, delaying gratification, and forever challenging your current comfort zone.

3. Emotions are contagious, so it pays to know what you're feeling. Think of the best boss you ever had. How did he or she make you feel? That's the way you want to make others feel.

4. When in doubt, ask yourself, "How would I behave here at my best?" We know instinctively what it means to do the right thing, even when we're inclined to do the opposite. If you find it impossible, in a challenging moment, to envision how you'd behave at your best, try imagining how someone you admire would respond.

5. If you do what you love, the money may or may not follow, but you'll love what you do. It's magical thinking to assume you'll be rewarded with riches for following your heart. What it will give you is a richer life. If material riches don't follow, and you decide they're important, there's always time for Plan B.

6. You need less than you think you do. All your life, you've been led to believe that more is better, and that whatever you have isn't enough. It's a prescription for disappointment. Instead ask yourself this: How much of what you already have truly adds value in your life? What could you do without?

7. Accept yourself exactly as you are but never stop trying to learn and grow. One without the other just doesn't cut it. The first, by itself, leads to complacency, the second to self-flagellation. The paradoxical trick is to embrace these opposites, using self-acceptance as an antidote to fear and as a cushion in the face of setbacks.

8. Meaning isn't something you discover, it's something you create, one step at a time. Meaning is derived from finding a way to express your unique skills and passion in the service of something larger than yourself. Figuring out how best to contribute is a lifelong challenge, reborn every day.

9. You can't change what you don't notice and not noticing won't make it go away. Each of us has an infinite capacity for self-deception. To avoid pain, we rationalize, minimize, deny, and go numb. The antidote is the willingness to look at yourself with unsparing honesty, and to hold yourself accountable to the person you want to be.

10. When in doubt, take responsibility. It's called being a true adult.