I got Favourable Circumstances using Notability ages ago, not to use so much as to have.[li]
Today I discovered something incredibly useful about that item. It lets you send Letters to other players from ANYWHERE items can be used, without any additional cost.
Here’s why: if you have Favourable Circumstances in your inventory, you can click on the item to pull up the “Write Letters” storylet where you can use it. That storylet is only accessible from your Lodgings, so sending someone a letter from, say, Doubt Street, is very inconvenient unless you use the aforementioned trick.
I doubt this was the intended use of the item, of course. If anyone from Failbetter reads this and wants to change it: please let us send letters independent of our location within the Fifth City. Any location that lets us use items should let us have access to the Postal Service, right? The forums aren’t used by the entire playerbase, and even fewer people check it regularly for messages. Letters solve this problem elegantly, and even have a small cost to disincentivize spam! Requiring the player to exit locations like Doubt Street and the Empress’s Court to use them, however, makes them much less worthwhile.