If you are reading this, you have probably have played Ikariam for a while now and you know the basics. Having 8 cities with no corruption qualifies you as a medium-sized player. You have enough gold coming in and have a respectable defence force. Hopefully you have followed my earlier advice and it is mostly navy. You have outgrown your warehouses and a lot of your resources are not protected. But this is alright, because you have CTs with all your neighbours, or otherwise they are friends or alliance mates. Nobody tried to pillage you for several months now.
What should be your next priority? Getting the ninth and tenth cities of course! You have 4 medium level warehouses per town and now the time has come to replace one of them with a dump. Chose your safest city: the one least likely to be attacked. Select a lowest level warehouse or failing that, one on the left and demolish it. Build a dump in its place. Low-level dumps are very cheap to build and soon you will have achieved a storage capacity of 350 000 required for a governor residence (GR) level 8. Move your defence forces to the city where you plan to upgrade the GR. Start shipping the resources to that city. If early in the game you have been prudent with finances and have not created useless armies, you should have been able to purchase 180 cargo ships by now. Set an overnight shipment of 90 wood to the town you are upgrading. Don’t tell anyone that you are going to upgrade a GR. It should be fairly easy to get your ninth city.
What should your ninth city be? If you followed my advice and already have marble, marble, wine, sulphur, crystal, wine, marble, wine, then your ninth city can be anything. What that anything will be depends on your circumstances and preferences. My ninth city is another crystal glass city because I like to work towards a high-level military future. If you want to grow fastest, though, and have a lot of online time, build another marble city. If you have little online time, build another wine city. Wine cities can look after themselves; I often don’t look into some of my wine cities for months on end. Don’t build a second sulphur city. It is a cheap resource and can be easily traded for marble. Store plenty of sulphur in all of your cities, keep it slightly above safe warehouse level, just in case a war breaks out. You may also consider to build a 9th city on a Hephaestus Forge or Poseidon island, as these two miracles are the most useful, and you are going to need them soon.
Keep upgrading warehouses and the dump. But once the dump reaches level 16 or 17 it becomes expensive to upgrade, so concentrate on upgrading warehouses. This is a rather dull period of the game known as “Warehouse Upgrade Hell”. But do not despair; there is always something to amuse oneself with. If it gets too much start taking breaks from Ikariam for a few days at a time, the game is quite forgiving. Do not activate the Vacation mode. All production stops and there is little to gain from this feature, unless you really go for a month to a location with no Internet access. If you are worried about going inactive and being deleted, you can purchase a small amount of Ambrosia. Ikariam is operated by a German company and under the local law your account cannot be deleted if it has an unspent balance of real money – be it just 1 ambrosia coin. Generally it is best to log in at least once a week to keep the account from going inactive and send wine and marble around. Inactive cities in central location attract pillagers far and wide, so beware.
How to survive Warehouse Upgrade Hell is separate topic. But my advice is, if you get bored take a break for few days. It is always exciting to came back and see how much marble and wood have accumulated! Anyway, getting a tenth city is still easy. And in 2-3 months you should have it. If your 9th city was crystal glass, make the 10th marble or wine. My 10 cities are: marble, marble, wine, sulphur, crystal, wine, marble, wine, crystal, marble. Another way to survive Warehouse Upgrade Hell is to go to war. Start taking active part in alliance military actions, if a member from far away is asking for help, launch your mighty navy and blockade the attacker. This is where your Poseidon and Hephaestus Forge miracles come useful! A tip: never launch directly at the target, but move navy first to an alliance city a couple of islands away. Surprise is your friend. Do not give them an advance warning. Read Ikariam War guide for more advice.
In between upgrading warehouses upgrade all Town Halls to at least level 26, taverns to level 30 and museums to level 12. This should ensure a reasonable amount of population and hence of gold income to support your expanding military.