<div id="logo"></div> should be a
h1, otherwise the document outline wouldn't be correct:
<h1><img id="logo" src="logo.png" alt="Progress Business Company"></h1>
See https://stackoverflow.com/a/14920215/1591669 for an explanation.
<div id="banner"></div> doesn't contain main content, it should go in an
aside element, or, if it can be understood as part of the header (probably on each page of the site), in the
<div id="main"></div> you could use a sectioning element here. I assume your
div contains a heading ("Welcome, dear visitor!"), so you have something like an implict section anyhow. Why not make it explicit? So use a
section instead of the
div (depending on the actual content,
article might be suitable instead).
#content > aside →
I'd say on the front page the testimonials could be considered part of the main content (in the end it depends on the real content/context), so instead of
aside you could use
Each single testimonial should be in its own
article, of course.
#extra > article →
I don't think
article elements in the
footer are suitable for that kind of content (unless your actual page contains something different). (Only the newsletter form could possibly get
article instead of
section, but that's not that clear; personally I'd use
section for it, too).
So, I'd go with
section here. If the contact details listed under "Address" are relevant for the whole page, you should use the
address element, too.