A glitch in Google's ranking system for Web searches led the company to make a change during the weekend, so the Vatican's Web site didn't rank below a site with information on pedophilia, according to Bitcity. The site reported Google's explanation for how the mistake might have occurred.

Alan Bleiweiss gives us the highlights from the "Blueglass L.A. Session: How to not FAIL at getting search traffic," where Vanessa Fox, Nine by Blue founder, and Adam Audette, AudetteMedia president, gave their perspective. Building search into a content development process, clarifying business goals, and SEO dos and don'ts are among the topics the two covered.

Understanding target keywords for a Web page remains a key focus of SEO development, though search algorithms evolve to understand context and attitudes based on advanced semantic analysis. Richard Hartigan provides a five-point checklist marketers can use to determine target keywords for a any Web page.

Rand Fishkin gives us a sample of his self-declared biggest SEO mistakes in hopes of preventing marketers from making the same. The topic range from reciprocal links and tobots.txt nofollows, to not using XML sitemaps, to incorrectly redirecting Linkscape to Open Site Explorer.

Dan Friedman, from the Inside AdWords crew at Google, tells us about a new keyword targeting tool the search engine rolled out globally in most languages:the broad match modifier. Friedman explains how, why and when to use it. A graph illustrates the relative reach of different keyword match type strategies. You will find this feature by logging into your AdWords account, through the AdWords Editor and through the AdWords API.

Elise Redlin-Cook talks with David Mihm from GetListed.org to find out how the company helps small business owners claim their listings on major search engines. The two cover a variety of subjects, from the value of paid listings versus free listings, to the top local search ranking factors today.

The Microsoft and Yahoo transition team's put together a video illustrating how the upcoming combined paid search marketplace will help marketers reach Yahoo Search and Bing customers through Microsoft's adCenter. The two companies, which plan to provide additional details soon about the transition, will together own about 30% of the search market.

Research from BIA/Kelsey suggests Yellow Pages will gain 39% of its revenue from video, SEM/SEO, mobile, social and reputation management by 2014, according to Liva Judic. She runs down some recent numbers for the study, including estimates from the U.S., Europe, Asia-Pacific and Latin America.

Christine Laubenstein explains how to become an affiliate marketer. She says revenue for affiliate advertising can range from a couple of cents to a couple hundred dollars per action. The amount you get paid depends on the value of the product or service for sale, as well as the particular affiliate program the company has in place. So, Laubenstein details the steps to get started.

Stony deGeyter tells us a targeted phrase isn't always as it appears, so marketers shouldn't only rely on keyword research. Among other advice, he suggests looking at other industries to see if they use the same terminology.