I'm sure some will return, but the default as of now is to not spend on Twitter. From my friends who buy ads at big agencies, they are actually quite happy to n

I'm sure some will return, but the default as of now is to not spend on Twitter. From my friends who buy ads at big agencies, they are actually quite happy to not deal with the smaller reach and platform - but felt they needed to, in order to show their clients "effort". In addition, there is general belt tightening, and ad spends are the first thing to get hit. Going after the smaller ad networks reduces the effort to maintain campaigns; add in that there is a reason to drop Twitter instead of across the board reduction, and I think this is a problem for twitter. I'd wager that 50% of the dollars that left aren't going to return, if not more.