The short version: if you can get this for under £18 it's the cheapest way to get gametime.
It's also the only way to 'gift' playtime without a credit card.
N.B., you can't add playtime to Trial accounts. You need to buy a full version of the game (World of Warcraft (Mac/PC),etc) first.
Longer comparison of the 3 main ways to pay for playtime:
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1. Buy it here:
Good points
- Perfect gift for a wow player. Nice box etc.
- Cheaper than other methods - so long as list price here is under £18
Bad points:
- Postage delay
- can only get 60-day
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2. Buy playtime through Blizzard's official online store, via [...]
Blizzard online store will email playtime codes, currently @ [...] = 30 days, [...] for 90 days or [...] for 180 days.
Good points:
- No postage times,
- No 'useless' box to throw away,
- No need to enter your card into your friends account.
Bad points:
- You need to use a credit card (Visa, Mastercard, and American Express) - debit cards are NOT accepted.
- No 'fancy' box.
- Can't get 60 days (but 2 x [...] = [...]).
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3. Put your card details into the account online.
Choose how often you want to pay. [...] One-Month, [...]Three-Months, [...] Six-Months.
Good points:
- No postage times,
- No 'useless' box to throw away,
- smaller £ to pay each time (for one month playtime) - though it's more expensive £-per-day.
- accepts debit and credit cards - Visa , Electron - Visa, JCB, Mastercard, American Express, Maestro, Solo, Delta
Bad points:
- you can't pay for a friend's playtime without entering your card details into their account.
- currency is based on the *players* account.
For example, if I pay for my european friend, I pay around [...] instead of [...] per month, due to it being charged in euro.
Corrections welcomed ;)