title: Sync vs Async in DFP
body: <p>I haven't signed up for DFP Premium yet, but I had a question about it.</p>
  
  <p>If I choose to use asynchronous DFP tags on my site, what happens if my site loads a line item for an advertiser that only has synchronous tags? Will the DFP placement still load asynchronously? Will DFP try to 'convert' a sync tag to an async one? (I have heard of other adservers doing this...). Also, what happens if the advertiser tag contains document.write().... will it still work to put that advertiser in an asynchronous DFP setup?</p>