The concept is fantastic - have all your listings translated and listed in large countries!
But wait! The translation only applies to the listing description. The body of the text remains in the original language. There are a couple of standard logo type phrases in the local language but the main text stays the same.
You have to pay the local fees for listings, German fees are very sneaky! They charge for items that are free on other sites, this can lead to costs that eat up any profits.
WebInterpret are incredibly helpful in the trial stage, not so much when you are fully signed up! You can opt out of the contract on a month by month basis so you are not committed to a long term obligation.
We did increase our business during the run up to Christmas so other users might get a benefit.