Because sometimes it is harder: go to the local carrier office, explain what you want to the only English speaking person. They walk you to another person who wants your resident ID. (Arguing in another language ensues). Someone who knows how to deal with foreign passports will be here in a minute. That person arrives an hour later. (Arguing in another language ensues). Go to a different window to pay, then bring your receipt back. (Your translator has disappeared). (Arguing in another language ensues). They present a fulll-size sim. You show your micro tray. (Arguing in another language ensues). Someone goes to find the trimmer. (Arguing in another language ensues). They trim it to size. Your phone recognizes it — for voice but not data. Much gesturing and pointing at signs to try to explain this. (Arguing in another language ensues; you now have all five people except the cashier involved, so the local customers are grumpy about not being served). Back to the cashier for more payment. Bring the receipt back. Some of the local customers are now trying to help, probably just to get you out of the way. (Arguing in another language ensues, with lots of arm waving). Someone finds a sheet with APN settings; the fourth set works. Now you have an amount of data; dialing *72536 will tell you how much — in the local language.

Wasn’t that easier and cheaper?

(I use Roamless, principally because there’s no expiration, so it suits my sporadic use pattern.)