It'd be nice if questions about travel to country X were more likely to appear in the cross-site ads in "X Language & Usage" stack exchanges. For example, japan questions appear on Japanese Language & Usage, and germany, austria, etc. on German Language & Usage.
People on the relevant Language & Usage web site are either more likely to want to know information about the corresponding country, or are more likely to be able to provide information about the corresponding country.
For those not familiar with cross-site ads, the following is an example of a cross-site ad linking to the Japanese SE (well, except for the minor fact that the ad itself was on the Japanese SE!)
I'm not sure what the "secret sauce" of cross-site advertising is, but it seems to be non-random - I see far more ads for certain Stack Exchanges than for others.
Of course, this shouldn't be over-done - only seeing travel questions advertised when you're at a L&U site might become wearisome after a while.