A common question on the forum is how should a person add seats to their stadium. Should you build the stadium or should you build seats?
Quick answer: Add seats and save the stadium to the end.
When you start the game, you have a stadium with 200 seats. The stadium upgrade option that is available will add 800 seats and increase your stadium to 1000 seats. This upgrade takes 16 days and costs 180K. If you choose this option, you will commit yourself to enlarging your stadium for the next 16 days. When the upgrade is done in 16 days, your stadium will have 1000 seats.
Along with the stadium upgrade, you have 3 other options of just seat upgrades: small, medium and large. Each upgrade adds an increasing amount of seats for an increasing amount of money and an increasing length of construction time.
small adds 200 seats and costs 60K for 5 days
medium adds 400 seats and costs 100K for 9 days
large adds 600 seats and costs 140K for 13 days
What the game does not tell you very clearly, is that after you do the small seat upgrade, the cost and length of time required for the medium seat, large seat and stadium upgrades DECREASE. Also, the amount of seats they add will also decrease. So, after doing a small seat upgrade, your stadium will have 400 seats. The seats added and their cost and time required for the remaining available upgrades are:
medium adds 200 seats and costs 40K for 4 days
large adds 400 seats and costs 80K for 8 days
stadium adds 600 seats and costs 120K for 11 days
After doing a medium seat upgrade, your stadium will have 600 seats. The seats added and their cost and time required for the remaining available upgrades are:
large adds 200 seats and costs 40K for 4 days
stadium adds 400 seats and costs 80K for 7 days
After doing a large seat upgrade, your stadium will have 800 seats. The seats added and their cost and time required for the remaining available upgrades are:
stadium adds 200 seats and costs 40K for 3 days
(Did you notice that each upgrade added 200 seats and that the original upgrades were multiples of 200 (400, 600, 800)?)
After doing the stadium upgrade your stadium will have 1000 seats and 16 days will have passed and you will have spent 180K, the same length of time and amount of money you would have spent if you had chosen the 16 day stadium upgrade. The next stadium option (villiage) will be available and the 3 different seat upgrades will be available again. The next stadium upgrade adds 2000 seats to your stadium (1000 seats to 3000 seats) and the seat upgrades add 500, 1000 or 1500 seats. (notice, the upgrades are all multiples of 500)
So why increase your stadium's seat over 4 short upgrades instead of 1 long upgrade?
1) Spreads the cost over 4 small payments instead of one large payment.
2) When you are done building a seat upgrade, you have a larger stadium and can sell more tickets. More ticket revenue!
3) You can build other facilities in between the seat upgrade. Add 200 seats, then add parking, add 200 more seats, then add youth, add 200 more seats, then add utilities.
4) It is possible to build your stadium too quickly. In level 1, the maximum attendance you can obtain is 800 fans. (the level 1 field stadium with the large seat upgrade. When you get to level 2, the maximum attendance you can obtain is 2500 fans, the level 2 amateur stadium with the large seat upgrade. Because of this, you should do what I suggested above in #3)
Hopefully I've done a good enough job explaining why you should do the 3 seat upgrades first, and then the stadium upgrade. If not, ask questions. If you have suggestions for edits, please let me know.