I’m trying to implement DoubleClick on a client’s site and having a heck of a time. Part of the problem is that when things don’t work, things just don’t work. Nothing is logged to the console, no alert boxes appear, no uncaught exceptions are thrown, nothing. Nevertheless, through experimentation, I’ve managed to get things to the point where iframe tags are being inserted in the positions where the ads should be on the page; it just seems that the iframes aren’t having src attributes given to them, so they’re just appearing as blank areas on the page.
It would be wonderful if someone had an answer on how to solve that exact problem, but failing that, I’d settle for a way to coax the DoubleClick script into just making a bit more noise when something goes awry. When I look at the minified/obfuscated script being loaded from Google’s servers, it does look like there’s plain English strings woven in there representing various error cases, so I presume there’s a way to make it display those strings to me…
From my understanding the iframes will not have src attributes… I think the reason they are used is as a form of sandboxing so that ads cannot interfere with the parent page in any way… an iframe allows different css, scripts etc without it conflicting.
If your ad units on your page are appearing blank then it is most probably because there are no line items that match… make sure you are using the build tags tool inside DFP… that hasn’t failed me yet… also check out the debugging console, this should display any errors that you have with your page.