Google’s latest search engine algorithm will impact 35 percent of search engine searches, according to Google Fellow Amit Singal. Hint: it’s all about recency AND relevancy.

Google announced its new ranking algorithm change last Thursday. It builds on the Caffeine web indexing system, which Google introduced in 2010 to allow the search engine to quickly crawl and index the Internet for fresh content on a much larger scale than before.

U.S. mobile social media usage rose by 37 percent in the past year, with 72.2 million Americans accessing social networking sites or blogs via mobile device in August 2011, according to research by comScore, Inc.

Almost 40 million U.S. mobile users – over half of the estimated U.S. mobile social media audience – visit social media sites via mobile each day, reports the research firm.

comScore’s research also shows that, right now, more mobile users access social media sites via their mobile web browser than via a social networking app (42.3 million compared with 38.5 million).

This is likely to change, however. The growth in users accessing social media sites via social networking app is much higher than the growth in access via mobile browser. In the last year those accessing social media sites via mobile browser rose by 24 percent, compared with the huge 126 percent growth in the audience for social networking apps.

1 in 6 Americans or 15 percent of U.S. adults now use an e-reader or electronic reading device, almost double the 8 percent in 2010. What’s more, of those Americans who don’t have an e-reader, 1 in 6 plan to get one in the next 6 months.

Based on a Harris Poll of 2,183 adults in July 2011, those with e-readers also tend to read more than American adults in general. While 16 percent of Americans read 11-20 books per year and 20 percent read 21 or more books per year, a third of e-reader owners (32 percent) read 11-20 books a year and over a quarter (27 percent) read 21 or more books per year.

bigmouthmedia’s 2011 survey of U.K. affiliate marketers reveals that search engine optimization (SEO) and content marketing are the most popular Internet marketing tactics for generating traffic and sales. Affiliates are also embracing social media, with many using all three as well as other marketing tactics.

Here are the top 5 affiliate marketing trends noted by bigmouthmedia:

More people are ‘Liking’ or sharing shopping items or links with their social media followers than forwarding them to friends via email, recent research shows.

A Responsys study of top online retailers finds that their use of ‘email-to-a-friend’ or ‘forward-to-a-friend’ via email has declined 15 percent since 2009, while the use of buttons and links enabling consumers to share with their social media network has increased by 12 percent.

When it comes to the most popular categories among daily deal website users, florists, malls, restaurants and day spas top the list, according to Scarborough Research.

According to Scarborough Research, local businesses most likely to benefit from targeting daily deal site users are restaurants, general retail stores, local specialty stores, health and fitness businesses, and automotive repair and servicing businesses.

comScore, Inc’s 50 most popular U.S. websites for July 2011 shows Google sites accounting for the most traffic, followed by Yahoo!, Microsoft, Facebook and AOL.

In detail, the top 50 U.S. website properties, along with their monthly estimated unique visitors for July 2011 are as follows:

In a sign that online advertising has truly gone mainstream, eMarketer estimates that retail and consumer packaged goods (CPG) will account for the biggest share of new U.S. online advertising spending in 2011.

Overall, the research firm forecasts online advertising to grow by 20.2 percent to reach $31.3 billion this year. Retail already accounts for the biggest share of online advertising and is expected to grow by 24 percent to reach $6.78 billion. The CPG industry will grow by 14 percent to reach $2.46 million in total online ad spending.

The number of mobile social network users is expected to grow from 1.1 billion worldwide in 2011 to 1.9 billion by 2016, representing a cumulative annual growth rate of 11.8 percent over the next 5 years.

Based on research from Visiongain, the outlook for mobile social networking is positive as market players and users alike experience changes in monetization models, fervent competition between vendors, and localization trends.

Online retail sales reached $37.5 billion in the second quarter of 2011, an increase of 14 percent over Q2 2010, according to comScore.

The rise in ecommerce spending represents the seventh consecutive quarter of positive year-over-year growth and the third consecutive quarter of double-digit growth.