William Hesketh Lever once said, "Half the money I spend on advertising is wasted, and the trouble is I don't know which half." For over a decade, it's been promised that online advertising will fix that. On that note, we made nice with Brooke Hammerling, the bicoastal tech insider who observed that no one can agree on metrics, whether you're talking click fraud or online video downloads. (We've picked ours — pageviews — and we're sticking to it.) Companies like Kiptronic, which hosted the Revision3 party last night, have engineered interesting technology for counting videos, but in any case, you still need humans to move the inventory. At the Adroll party at Slide, silver-tongued founder Jared Kopf was seen giving his pitch — "price discovery algorithms" and "social discovery" — to Alan Cutter, CEO of ACLion, an ad-sales recruiting specialist. Cutter told us that he has a database of over 150,000 ad-sales executives; he's the guy you go to when you need to hire a salesperson in New York. Photos of some of the people who sell every last slice of the advertising pie, and convince you that the half that doesn't work tastes just as sweet: