Social Media:

• Tumblr now reaches 120M people each month.

• YouTube hits 4 billion daily video views.

• Google doubles Plus membership with brute-force signup process.

• Larry Page wasn’t lying about the Google+ engagement numbers.

Search:

• New mobile AdWords targeting options: WiFi & OS version.

Mobile Computing:

• Apple sells 350,000 textbooks in three days, analyst says.

• Tablet, e-book ownership soaring, study finds.

• iPhone 4S and iPad 2 receive first untethered jailbreak.

Business Strategies:

• Google to dial up slower growth.

• Google kills more services.