Photos 1 and 3 are potential stock sellers. It's not a very complicated thing to sell stock editorial, which is mainly used by magazines, textbooks, newspapers and travel brochures (or their equivalent websites). Selling stock for commercial advertising use is very different, you would need a signed model release from every single individual even in the silhouetted group, and for the water thingy (not a banana, but what we call a banana!) you would need a property release from the maker and/or owner.
For this reason, although I am a professional photographer, I have never sold commercial/advertising stock - only unreleased editorial.
Examples from this week:
I could never have got model releases, and I doubt that Cunard would have provided a property release - in fact, if asked they would probably have told me that photography on board the QE2 was not permitted (I have sold many pictures taken on this short 3-day cruise, which was a Pentax press event).
As for this one, it's the interior food court of a well-known UK shopping mall. It was taken on a Konica Minolta A2, anything bigger and the security guards would have thrown me out. For commercial use every single person in the scene would have to sign a release, as well as every business owner for property. This shot and another taken at the same time have sold for newspaper use in the UK several times. Technically, I am not 'allowed' to take such pictures on private property, but I place them on Alamy clearly marked as no property release available. They are normally used in stories about shopping, or places to visit, or the economy etc. So far the owners of the mall have not contacted Alamy to complain - I presume they welcome the publicity, even if they would try to prevent photography when asked.
I used to think that the amount of return from the pictures was not worth having, but on checking my Alamy account (started in 2002 with just 15 small images, now unacceptable, 5 megapixel JPEGs) I have steadily increased the filed images so that now there are more than 8,000 - but I have not done any extra special shoots for this, it's just my daily snapshots and travelling. The sales just passed the overall $30,000 mark and only 250 sales have actually been made, with a good number of those repeats - certainly no more than 200 of the 8,000 pictures have so far found a use.
David