I'm in agreement with you and John here. I believe "webshop" is primarily used internationally, outside the U.S. Since this site is accessed throughout the world, we occasionally see regional or less commonly used terminology here. For example, thanks to this site I now know that web hosting services are also known as "web hotels" in some parts of the world...
This is a perfect case use of what tag synonyms are for: tags that essentially mean the same thing, with one being more commonly used than the other(s). Users from different regions will still be able to find a suitable substitution by typing in the term they're familiar with.
I therefore made webshop
a synonym of the target ecommerce
tag, and merged the questions so that the ecommerce
tag will appear in replace of the webshop
tag. When someone starts to type in "webshop" as a tag, ecommerce
will pop-up, indicating that's the more commonly used tag on this site.