[NTG-context] Spacing after defined word: beginner's question

[cormullion at mac.com]

This must be a beginner's question, but I can't find the answer to it  
in the manuals...

Take this ConTeXt source:

--
\def\Acme{%
	{\ss\sc ACME}}

Welcome from \Acme. \Acme make fine products.
--

When this is made into a PDF, it looks like this:

--
Welcome from ACME. ACMEmake fine products.
--

- because I didn't have a space in the definition, I don't get a  
space in the second sentence, but the period didn't interfere with  
the execution of the first occurrence. But if I put a space in the  
definition after the 'E', I get this:

--
Welcome from ACME . ACME make fine products.
--

- and there's a space after the first 'E', which I don't want, even  
though there is now a space after the second...

What am I doing wrong?