[jmnicolas]

I'm French. Most (99.9%) of my countrymen (and women ;-) won't bother with something that is not translated.

I think (but not 100% sure) that it will be the same in southern and eastern Europe.

Northern Europe should be different, they're usually better at learning English.

[icebraining]

Same here. I've worked in B2B SaaS companies that had clients in Belgium, Portugal, Spain and the Czech Republic, and decent localization (both translations and date/currency formats) was crucial to get our clients. This has been true from two-person companies to multi-million euro companies. Unless you have no real competition, I would advise against ignoring it.

Also, if you want to land a governmental bid to provide software for some department, it might even be a legal requirement.