Social Media:

• Facebook friends for sale as advertising seeks clicking cliques.

• Facebook said to be working on phones with INQ for AT&T.

• LinkedIn to acquire business review start up.

• Foursquare experimenting with recommendations engine and "manufactured serendipity".

• Digg redesign alienates users.

Mobile Marketing:

• Apple's iAd for Developers is a (sometimes expensive) work in progress, app makers say.

Privacy:

• Schmidt:'Google doesn't do data mining.'

Ad Agencies:

• VideoEgg buys Six Apart to build 'conversational' media company.

Email Marketing:

• More Hotmail updates on the way.

Pearls of Wisdom:

• Mobile video advertising is irrelevant.