Reuters has gone big on Index Ventures partner Saul Klein this week. The former Skype VP who, as a VC, has invested in the likes of Last.fm, OpenX and Moo, appeared at the newswire’s Paris summit with words of wisdom on the value of social networks to traditional media. Bottom line: it’s a relationship based on dependence…

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“There are social media networks that have come from nowhere in the last three to four years that have built enormous audiences. But without a sales force you’re just not going to generate significant revenues and explain to advertisers what the opportunities are. The point when Bebo got acquired was just when they were starting to show monetisation and AOL (NYSE: TWX) has a sales force that has been selling online ads for 15 years. What they were missing was the audience.” He said the same thing of Last.fm and CBS (NYSE: CBS), which is working the social music site hard in the US on the advertising front. And big ad sales’ experience may be doubly important after forecasts for social network ad spending were cut this week.

Reuters’ video profile of Klein after the jump, and here’s my interview with Saul from October.