These webisodes, etc are tougher to find, so here's some links. It's funny to see the advertising in the Arrow and Flash webisodes
Blood Rush - between Arrow S2E05 and S2E06 :
Bose ad: https://www.youtube.com/watch?v=VTuMkfFQF0E
Chronicles of Cisco - between Flash S2E17 and S2E18 :
AT&T & TBBT ad: https://www.youtube.com/watch?v=6UHbq4MEINg
There's a Superhero Fight Club 3.0 now.
Superhero Fight Club 1.0 - is a promo for the final episodes of Arrow S3 and Flash S1 (arrives after Flash S1E18) : https://www.youtube.com/watch?v=EnLcV1ASZQw
Superhero Fight Club 2.0 - is more or less a promo for Supergirl joining CW. (arrives before Flash season 3) :
https://www.youtube.com/watch?v=a7SnhM6H900
(1.0 & 2.0 together: https://www.youtube.com/watch?v=qapP94Ia6rs)
Superhero Fight Club 3.0 - collection of Arrow, Flash, Supergirl, Legends & Black Lightning:
https://www.youtube.com/watch?v=VsWy1DAINDc
Constantine - watch before Season 1 of Constantine:
Modern Mystery: Tales of the Dark Arts - Who is John Constantine?:
Originally on NBC's site, but it was taken down:
https://www.nbc.com/constantine/video/modern-mystery-who-is-john-constantine/2821603
Modern Mystery: Tales of the Dark Arts - Who is John Constantine?:
(This has like one link anywhere, someone should reupload a backup)
https://www.youtube.com/watch?v=ks-Vy647FeA
Ravenscar Institute Patient Debrief -- https://www.youtube.com/watch?v=GQkSAaP99Eo
The Flash - Stretched Scene (Microsoft Surface ad)
https://arrow.fandom.com/wiki/Stretched_Scene
Stretched Scene #1 : Flash S4E06 : https://www.youtube.com/watch?v=5sQ0WaTrvSY
Stretched Scene #2 : Flash S4E07 : https://www.youtube.com/watch?v=y1WNHYWIxA8
Stretched Scene #3 : Flash S4E09 : https://www.youtube.com/watch?v=Q-EwHPqwcqQ
Netflix ad: Deleted scene : Flash S4E09 : https://www.youtube.com/watch?v=3p_zHfvTyuo
While getting these also noticed some of the official "sneak peak" promos were secret advertising:
Flash S4E07
Lyft ad: https://www.youtube.com/watch?v=MGq4wWO9Pm0
Youtube ad: https://www.youtube.com/watch?v=eB7YS6t0pWY
Another fun promo -- ad for Wonder Woman featuring Lynda Carter & Teri Hatcher
Supergirl mid-late Season 2
https://www.youtube.com/watch?v=GlWKaY6AxPY
