Get involved with a local realtor not the listing agent, they owe loyalty to the seller, and see what they say.

Their loyalty, their top of mind awareness of you, and their memory of your contribution to their experience (that they share with everyone they know) will make a far bigger impression on your wallet than a magnet on their fridge with your name on it. 

You can imagine where my loyalties lie ;)

Represent them the same way you would want someone to represent you.Beyond being ethical and good business, it also produces some nice side effects, like return business and loyalty

I also raise it $10 or $25 above what I actually seek in the letter, then I include a "5-star loyalty" (or some such) discount memorandum for paying on-time and in-full with no complaints.

I also believe that loyalty is earned over time.

It's funny because a smart investor in my mind partners with a quality agent and there is loyalty on both sides. 

1- When it comes to contractors, loyalty is not always a virtue.

Is there a genuine opportunity to create loyalty here?

Since they sell cheap gas to the public it breeds loyalty.