I think it's been more than a month since they ran a contest for avatar and signature design here in BitcoinTalk. Until now they still haven't started the signature campaign. It seems they changed their mind about running a marketing campaign here in BitcoinTalk. Good thing OP is still active; they just haven't posted updates or bumped the thread daily.
At the closing of the second round of the review campaign, the launch of the signature advertising program was announced. That was about 10 days ago. I think it is too early to write off such a possibility.
This campaign is officially close now.
Thank you everyone for participating on the both review campaign.
We are planning to launch the signature campaign soon.
Looking forward to work together with some of you.
Thank you Tumbler.io team.
Cheers.