I don't know about others, but I tend to see the same adventures being completed all the time (and the same ones ignored). Roaring Bull and Black Knights are the current favourites, because they offer the best value (now cheap to buy, 2 lootspots, low losses). This will always be the case - as the balance changes, other adventures may become more attractive, so the variation in adventures played is low.
I don't expect BB to keep monitoring and tweaking to try to balance the adventures and get more people playing more adventures. Why not get the code to do it for you?
Here's what I would do:
- Count the number of adventures available. For the sake of simplicity, let's say there are 21 different ones.
- Create an adventure with an initial popularity of 0. Each time someone plays it (and completes it) the popularity rises by 20, and each other adventure falls by 1 (so basically, the adventure takes a popularity point from every other adventure).
- Use this popularity figure to adjust the available loot. As the popularity goes up, the loot decreases very slightly. So, for instance, 500 granite in SFTR might become 499 granite.
- Conversely, unpopular adventures find their loot goes up. SOTV would increase significantly in the early days.
That's it - as simple as that. After a few days, Roaring Bull would be less attractive as the loot dropped, and SOTV would become more attractive. As people move away from RB, the popularity figure would drop and the loot would increase. People would naturally vary the adventures, for instance they might suddenly discover that Secluded Experiments was paying 2500 granite, word would get around, more people would complete it, then VtV would become the best adventure.
The best thing of all is that it requires no further interaction from the developers. It is self-balancing, like prices in the trade office. No need to accurately predict how much loot to offer. Just get it about right and let the popularity count fine-tune it.
It's also pretty simple logic to code. Make your base figure "1" and increase/decrease it by 0.01 (or 0.001, I don't know how often it is played per day) each time, then you just have to multiply the random loot e.g. 500 granite by the popularity figure, then round it.
This principle could be introduced elsewhere in the game too.