Digging into Stormy makes me think this seed was likely planted during the 2012 presidential election when it was thought Trump would run then and abandoned when he didn't. The affair is stated to have occurred in 2006 at a celebrity golf tournament held at the Edgewood Tahoe Golf Course (July 11-13, 2006) and sponsored by American Century Investments (Kansas City). Stormy states that Wicked Films (her employer) was paid to bring porn actresses to the tournament for "promotion" purposes (sounds like a honeypot setup).
Stormy said nothing about the "affair" until 2011 when she did an interview with InTouch magazine (pre-nondisclosure agreement by 5 years. Supposedly did polygraph with them). That interview was not published at that time. Interestingly, a website called The Dirty did publish the story in 2011 and was shut down by Stormy's lawyers with a cease-and-desist letter (The Dirty is now spinning it as Cohen afraid to send letter himself and worked a deal with her lawyers to do it).
Fast forward to October 2016- women start popping up accusing Trump after the Pussy Tape is published by the Washington Post 10/7/16. Stormy is one of these but her trail appears to start before the tape appears but I couldn't find hard dates. All I know is she started talking to Jacob Weisberg of the Slate Group "a few months before the election." She claims $130k was paid to her by Trump's long-time lawyer, Cohen, 11 days before the election to keep her quiet. During this time is when the nondisclosure agreement appears. Other names on the agreement are Keith Munyan, J.D. Barrale, Angel Ryan (aka Jessica Drake).
The Wall Street Journal begins publishing Stormy's story. Right after, InTouch releases its 2011 interview with Stormy. The InTouch article states the affair lasted to 2009/10, but a recent NBC article has Stormy saying the relationship lasted from "summer of 2006 well-into 2007." Did she forget what she said in 2011?
Now stories appear saying Cohen used a Trump.org email to facilitate negotiations and payment (they're trying to tie into FEC now with the story)- they even reference a subject line in an email dated 10/26/16 stating "RE: First Public Bank Transfer" with the message body confirming $$ deposited to checking. I could not locate an actual copy of the email but only did a quick dig because distracted with other angles. CONVENIENTLY, First Republic Bank flagged this transaction as suspicious and submitted a report.
www.nbcnews.com/news/us-news/michael-cohen-used-trump-org-email-stormy-daniels-arrangements-n855021
www.kansascity.com/news/local/article206557544.html
www.washingtonpost.com/politics/i-have-to-see-you-again-how-trumps-alleged-affair-with-a-porn-star-spilled-into-public-view/2018/03/07/4581514e-2229-11e8-86f6-54bfff693d2b_story.html?utm_term=.8f6e92c9b1fd
www.nytimes.com/2018/03/24/style/stormy-daniels.html
www.esquire.com/news-politics/a15526362/stormy-daniels-intouch-interview-donald-trump/
thedirty.com/donald-trump/exclusive-the-stormy-daniels-shakedown-of-president-donald-trump/#post-2235704