speaking as someone who&#x27;s actually purchased pinterest ads:<p>the review process is much more careful than facebook or google. they only really want content that would make sense organically on pinterest.<p>facebook and google are pretty loose about the &quot;salesy-ness&quot; of ads, but pinterest is pretty strict in comparison.<p>obviously with all these restrictions, agencies don&#x27;t like it because they have to cater their message to pinterest instead copy and pasting the same noise on every platform.<p>pinterest probably won&#x27;t kill google proper, but I could easily see pinterest killing google images.<p>When is the last time a company seriously decided to take on image search at google scale? Google doesn&#x27;t even show ads in it&#x27;s image search.<p>another reason agencies probably don&#x27;t like pinterest is the high fixed-floor bids of 10 cents.<p>you could have lower effective cpcs, but your ads actually have to be engaging, and they have to get repins and shares.<p>bottom line: Pinterest simply demands more effort from advertisers, and they&#x27;re pretty picky. Consequently, users don&#x27;t mind their ads as much.<p>The best case scenario for pinterest&#x27;s investors (in my mind) is an  acquisition by facebook as part of a strategy to take on the web search market.