In today’s “you win some/lose some” category we have, yep, Facebook. We reported earlier about Facebook’s troubles in Japan as it is Twitter who is challenging the local incumbent there for top spot among social networks. But fear not. In the all important metric of “making money,” Facebook is doing just fine, padding its lead as America’s largest online display ad publisher.

In fact, according to the latest comScore numbers, Facebook is larger than its next four (sizable) competitors – Yahoo, Microsoft, Fox Interactive and Google – combined in terms of number of display ad served up to web users, as the chart here shows:

We went back six months and looked at comScore’s Q1 2010 numbers and compared those numbers to the most recent round-up. In the U.S., Facebook has increased its market share by an impressive 6.9 percent since Q1. Yahoo, Microsoft and Fox Interactive, meanwhile, have all lost share in that time while Google has nudged up by .3 percentage points, good enough to knock AOL out of the top 5. In other words, Facebook is running away with the higher-margin display advertising business in the U.S. And, as we reported last week, it has an even larger lead over rivals in the UK.