It’s a mantra marketers might get sick of hearing, but it never stops ringing true: Test everything, because the results might surprise you.

That was the message from last week’s “Website Testing Wins” webinar, featuring Justin Rondeau, Chief Testing Evangelist and Editor of WhichTestWon.com, and Peter Borden, Marketing Manager at Monetate.

During the webinar, Rondeau and Borden presented dozens of website tests that taught companies major lessons when it comes to improving conversions, AOV, and customer satisfaction. And some of the learnings those companies uncovered were downright astonishing.

We picked four of our favorites from Rondeau’s presentation. Read about these tests, take a guess, and see if you’ve nailed it. And don’t forget to check out the webinar recording of Website Testing Wins for results and insights on the rest of the testing wins.

© 2012, WhichTestWon.com

Test #1: Palmers’ Product Display

Palmers.at, an intimate apparel retailer, wanted to test its assumptions about the number of items it displayed on category pages. Typically, when a user clicked on a category, they were shown a default of 10 different products to browse. But someone at Palmers asked why they were only showing 10 items, and whether that was effective. So the company tested displaying 10 products, and showing 50 products to discover what Rondeau calls “the sweet spot” for visitors.

Winner: Displaying 50 items on category pages resulted in a 35% lift in purchases.

Bottom line: Rondeau points out that a test like this one should highlight the importance of testing default settings on your website. Ask yourself if those default settings are really working, and then test them to see if you can find unexpected ways to move the needle.

Test #2: Mountain Equipment Co-Op’s Search Bar

Here’s a prime example of a small test having a big pay-off. Mountain Equipment Co-Op, which sells outdoor gear and clothing to members, decided to test the placement of its search bar. So MEC split-tested the placement of the search bar. The control group saw the search bar at the top of the homepage, in the upper right corner. The test group saw the search bar down near the homepage’s main nav bar.

© 2012, WhichTestWon.com

Winner: Placing the search bar closer to the main navigation of the homepage won, lifting sales by 12%.

Bottom Line: Testing the placement of search bars and checkout buttons on your homepage can make a big impact on the bottom line. One word of caution: Rondeau says companies have to optimize their search features and make sure backend search capabilities are working properly before running a test like this so they can get clear results.

Test #3: The Brewer’s Market Tries Bold Copy

Sometimes, the copy on your website can make all of the difference. That’s what The Brewer’s Market, a homebrew retailer, discovered when it tested different headlines and text on its website. For this test, one group of visitors saw a promo offer on the homepage that had a paragraph of text and a long headline. The other group of visitors saw a short, bold headline reading “The best damn beer they’ve ever tasted” with no other text.

© 2012, WhichTestWon.com

Winner: The shorter text won the day, lifting sales 18.7% over the course of three weeks. Brewer’s Market also tested the texts again, just to make sure the results were right. During the second test, the simple copy increased sales by 60.7% over the course of about a week in December.

Bottom Line: Risky tests, like adding bold headlines or removing text, are a great way to uncover real learnings about your visitors and what they want. But Rondeau also points out that a test like this one shows the importance of trying new things during the holiday shopping season. Since visitors are more likely to be shopping for other people, short text works because most folks just want to grab the gift and have it delivered. Meanwhile, that approach might not work during the rest of the year.

Test #4: Cross-Sell the Right Way

For one unnamed client, testing a new approach to cross-selling paid off. This company sells Tasers, and decided to test the cross-selling option on the landing page for a $500 Taser. During the test, one group of visitors saw no cross-sells at all on the landing page. The other group of visitors saw two cross-sell options that were relevant, with the company suggesting two other self-defense products that were much cheaper than the Taser.

© 2012, WhichTestWon.com

Winner: The relevant cross-sells boosted the company’s bottom line considerably, so much so that the company asked the results to be kept private.

Bottom Line: Rondeau points out this test is counterintuitive (most people would assume visitors wouldn’t want a cross-sell at all), however it underscores how effective relevant cross-sells can be. Offering a lower-price cross-sell helps ease sticker shock and stops visitors from bouncing from the landing page if they don’t have $500 to shell out.

Can’t get enough when it comes to ideas to test on your website? In addition the “Website Testing Wins!” webinar recording, check out the eBook, “13 Website Testing Wins.” It reveals campaigns that made online retailers millions of dollars in incremental revenue.

But wait, there’s even more! We’re launching WebsiteTestingWins.com, a crowd-sourcing website where online marketers can post and vote for their favorite articles and blog posts about website testing and optimization. Stop by, kick the tires, find great testing ideas, and tell us what you think!