There's sometimes an explanation for an extension. This one from the AAG appeared in an e-mail last week.
Due a high volume of submissions, the abstract deadline has been extended.I Googled the phrase above and found 3,220,000 hits from a variety of organizations. Clearly, the AAG is not alone!
Sometimes there's no explanation, but a gentle push to action. This statement, from Esri, also appeared last week.
We hope these few additional days will help those of you sitting on the fence make the decision to submit an abstract...While I've worked for organizations that put on conferences, I've not been involved in calls for papers or extensions. Here's the bottom line as I understand it: The papers/panels/workshops are the content of the event. If there's no content or not enough content, there' s no event. So, if there are not enough (or enough high quality) proposals by the deadline, organizers must ask for more.
I'm not sure how organizations decide if they have enough, but clearly over the years, they have a sense of how many proposals are needed to fill out the planned event. And, I suspect, those who propose papers to the same conferences every year have a sense which organizers typically offer an extension! My sense is the AAG and Esri always extend their deadlines.
Does it matter?
As someone who keeps deadlines in mind and mostly meets them, I find these extensions frustrating. Why should I organize my time well and get my proposal in before the deadline while others dawdle and are rewarded with an extra week?
For everyone else it seems there's no harm done. Organizers can collect more proposals and perhaps put together a better conference. They may even bring in more money from the event. Procrastinators get a chance to get a speaker slot. And, no one need know they are not as organized as anyone else! Students who ask for and are granted extensions for papers during their courses will feel right at home with conference paper extensions.
It seems extensions make everyone happy. I expect we'll see them for these larger conferences for some years to come.