4 part Q&A for Google Local Results & Positioning

Even a 'theory based' guess would be welcome!

Google local typically returns a thumbnail map and (3) local listings returned labeled with A-B-C map pins.

1st question:
"How does Google determine what 'Listings' they will show first, second and third? Are these results;

Purely geographical?
Random?
Based on traffic?
Amount of Backlinks?
Ranking actor?
Length of time listed in Google local?
Age of the domain?

2nd question:
"Why do these A-B-C map pins never match the the A-B-C map pin results when you click to view the Large Map? In other words the first 3 listings on the local details page display in a different order.


Other miscellaneous results I have seen, but are not particularly important

~ Sometimes the THUMBNAIL MAP displays in the middle of the Google results page. It does not typically happen all the time, but I have seen this before. Is this a random occurance as well?

~ Just today Sept. 30 I noticed that Google is showing my 2nd photo instead of the first photo for my listing. (these are shown when you click for the listing details). Again... no big deal - but it shows that somebody behind the Google curtain is tweaking the code.

 

i did not see any relation between your post and adsense .

can you elaborate it pls?