It's a company asset, no different in how I can write my internet, hosting expenses off on the company I operate.
Your internet bill or hosting expenses is not an asset, it's a normal business expense so it can be offset against your tax bill.
Anything with a resale value however is an asset and they fall under different rules (at least in the uk). You can only offset the difference between what you paid and what the item is now worth & you do that over multiple years. If the item increases in value then next year you'll have to pay tax on the increase.
I can write down such expenses at tax time and basically come out even on them.
What do you mean come out even? You've still had to pay the money, you just won't be taxed on it (as you don't have the money anymore). With an asset it's different as you still have it, so you're taxed as if you still have the money that you earned. A lot of companies lease instead of buying assets because it can have tax advantages
http://www.hmrc.gov.uk/manuals/blmmanual/blm00705.htm
