The advertisement board above can be updated. In order to own this advertisement board, you always have to specify a sale price. Anyone can buy it from the current advertiser at any time for the specified sale price. Whilst held, a 5% fee (pa) is levied as the ads board maintenance fee. When buying the ads board, you have to specify your starting sale price along with an initial deposit[both denominated inETH] and specify your advertisement. At any time, someone can buy the ads board from you at the specified sale price. As you hold it, a maintenance fee will continuously be collected from the deposit towards the ads board operator at 5% of the price you set per annum. If your deposit does not cover the maintenance fee anymore, the ads board can be foreclosed by the smart contract steward for safekeeping. You can top up and withdraw from your deposit at any time. You can change the price at any time [higher/lower]. You can change the advertisement content at any time. When someone else buys the ads board from you, your remaining deposit is returned. DISCLAIMER: This is very experimental. The smart contracts have NOT been audited. Only participate if you can afford it.