My travel stuff and everything else such as business and food all sell about equally. Probably varies from person to person because everybody shoots differently.

its good to see you are thinking of that, I do that all the time, looking at my own files/sales but it hard to draw a picture because you pretty much never know, sure quality is what matters more but a file that have sold once or never might be a cool sale tomorrow, have many files with 1 or 2 sales but with OD sales or even EL, I believe the key is to improve, we all know that yep

I think the bottom line is that it depends on what travel pictures you shoot

If I just shoot a pretty beach, it may not sell (unless there's a lovely woman or some beer or something iconic on it). If it's in a well travelled tourist destination, it probably will. If there's a clear story - luxury, relaxation, love, family time - that will work even if the place isn't recognizable.

Shots of keyholes, wooden doors, old hinges and churches in unrecognizable places are less likely to sell. I've never spent money on travel for stock. I just shoot wherever we're going anyway.

As far as where the shots need to be, with SS you can see where the shots are being purchased, and I'm sometimes surprised to see a shot of a beach in Maine being purchased in Australia or Japan (this morning it was from the Northern European coast; perhaps there's somewhere there that looks similar?). I think you just need a large-ish pool of buyers to be interested in that place or subject matter.

LOL! Yeah, I have sold more pics of a spoon on white than all my travel pics combined! So Why do I carry almost 35 lbs of camera equipment around while climbing up a dangerous mountain (Yellow Mountains in China)! I wanted the best pics possible and now most are being rejected due to having sharp contrast- deep shadows. You Think! Of course there is sharp contrast because it is real lighting by nature to include rain, fog, mist, sun and clouds. If only I could control those elements but if I was able to control those things I sure as heck would not be taking photos for money lol!

35 pounds?
Ja, thats why I bought the 18-200 mm.
Also didnt you know that it was forbidden for photographers to go to China before they can do HDR?

From a purely financial point of view, it makes sense to stay at home shooting objects and textures, but it's boring.

And one day you might find that the objects are somehow copyrighted.

If you love to travel and love to shoot, bring your tools.  Income from your travels is icing on the cake... and money for the next trip.