That being said, I think much of the grayness is for a reason. Brutal frugality will choke a business nearly as much as overspending.
In my facetious examples, the European vacation actually would be for customer acquisition. There would be a meeting or two with potential customers, but they would still fly first class and stay in top hotels, plus have a few extra "fun" days.
The motorcycle really would be for testing, but they may think what's the harm in taking it home for personal use in between testing sessions?
Kim Dotcom in 2000, posing with his model girlfriend in front of a superyacht…a year later he had multimillion euro investments from TÜV and BMP.
Want the company to buy a motorbike or car for "Product testing"? Totally legit - but it belongs to the company. Use it for personal use, and in most countries you'll be hit with a tax bill.
Mixed-purpose trips such as "Customer acquisition in Europe"? There are specific rules governing whether/how it's taxed: http://www.lewis-knopf.com/newsletters/financial-rx-article/...
Pesky taxmen. They thing of everything.
But that's what parent was talking about, buying toys and parties and such and why investors don't notice. Cause they call it by a different name.