It's all over the board. I tell my clients I need about 10 days once we are ready for photos to get all the marketing material ready.

ALL my listing agreements have a 'listing to be up in marketing by' date . . . usually 7 days after ink. I need time for all the marketing plan items to be ready and that depends on how busy the photog is. 
IF the property needs to be cleaned/cleared  . . . marketing to begin once property is ready . . . if the owner doesn't do their part, they are in breach.

One listing was signed and I was ready to go, but A YEAR LATER the owner was still making excuses why he could not fix and clear for photos and marketing. I let the listing expire, having never hit market . . . and 5 years later the property is still as it was then. Repair issues, clutter issues, code violations . . . 

12 days is average for me the last 2 years.

I like to get all the marketing done and launched to build an awareness & interest before going from Coming Soon to Active on the MLS. 

The association and my broker are extremely zealous about enforcing the rule that a listing must be live within 72 hours of the client signing the listing agreement. Actually, that might be 48 hours. I checked. It is in reality 24 HOURS.

And yes, we now have a compliance person who is guilty of overeach.

On average, about 7 days.

The listing agreement is signed prior to photos being taken, and then usually the home goes on the market within a few days.

Depends on the situation.  Some could be 4 or 5 days others months up to a year depending on how much pre-list work on the home is needed, staging etc. Just put one on the market today that they literally started preparing over a year and a half ago. They did a great job.

That's a very large "it depends".  I like to have the agreement signed as soon as possible.  Sometimes there are months between that signing and 'active'.  And sometimes the seller is counting the hours.

I'd say on average, allowing for photos, floorplans, de-cluttering, etc... somewhere between 7days and 2weeks.

On average, a week.  

It depends...

There is often more involved than staging even if the house is vacant.

All our photos are done by a pro...including drone shots and 3D tour.

We may manage the installation of new counter tops, refacing cabinets, new flooring or carpet, new light fixtures, new appliances, upgrading a kitchen and/or bathrooms, painting inside/outside, landscaping...and more if needed. The upgrades and improvements often take care of issues that would surface in an inspection and add value far beyond the expense of doing the work. 

We rarely get a listing for a house that is "market ready".

It's all over and depends on the property. Sometimes just a few days but have had several properties where it's been weeks for preparations.

No average ... it can be like clockwork per the proposed schedule or it could be the opposite. Once the seller is ready, or I have completed what needs to be done on the seller's behalf, I can go live on the MLS in a few days. 

Most of the time is around 7 days but there have been delays up to 14. The seller getting ready is what takes the longest.