To stay on top of the latest trends in online marketing means reporting and analyzing an assortment of topics — from ad networks to social networks. The top 11 news articles published by ClickZ’s news team in 2009 offers insight into online marketing’s evolution, plus includes a tribute to ClickZ’s cofounder Andrew Bourland who died in February.

1. YouTube Plans Redesign to Highlight Premium Content

YouTube plans to separate its premium and long-form programming from user-posted videos. March 30, 2009

By Zachary Rodgers

2. Agencies Break Away From Ad Networks

Vivaki, Razorfish, Mediabrands, and others buy display ads direct from exchanges. Will the ad network herd be thinned? Oct. 12, 2009

By Zachary Rodgers

3. Businesses Turn to Twitter to Cut Recruitment Costs

The value of Twitter as a platform for finding new employees, however, remains unproven. March 24, 2009

By Jack Marshall

4. The Gap Steps Up to Social Media in New Denim Campaign

Campaign has no TV commercials, places greater emphasis on Facebook and online advertising. Aug. 17, 2009

By Douglas Quenqua

5. Vertical Ad Networks Clash With Custom Targeting

To reach niches, many ad buyers choose between vertical aggregators and large networks with advanced targeting. Jan. 12, 2009

By Zachary Rodgers

6. Girls’ Retailer Builds Virtual World for Tweens

Speciality retailer plans extensive tie-ins between its virtual world and more than 900 real-life stores. March 4, 2009

By Douglas Quenqua

7. ClickZ Cofounder Andrew Bourland Dies

In his final weeks, the entrepreneur embraced the medium he so loved and reached out to friends and followers. Feb. 16, 2009

By Anna Maria Virzi

8. Ad Operation Failures Dog Agencies, Crippling Client Campaigns

Only a minority of campaign impressions ever reach their intended audience, researchers say. March 3, 2009

By Zachary Rodgers

9. Display Ad Prices Fell 50 Percent in Q4 ’08

very vertical category suffered steep declines compared with the year-ago period, according to PubMatic. Jan. 15, 2009

By Douglas Quenqua

10. Despite Debate, Brands Find Value on Twitter

While detractors argue brands don’t belong on the quick messaging platform, brands like Ford, Dunkin’ Donuts, and Whole Foods are on Twitter. Dec. 29, 2008

By Kate Kaye

11. How ‘Yes on Prop 8’ Campaign Took the Web by Storm

Conservatives won the Web effort in California’s intense fight over same-sex marriage, and voter-file data matching was just part of the strategy. April 6, 2009

By Kate Kaye

Note: This list is based on ClickZ news articles that received the highest number of page views in 2009.