For business, I'd never use Blogger or WordPress.com.
It's by far best to use a self-hosted WordPress installation, from WordPress.org.
Here are 6 very important things to ask yourself before you make your choice:
1. Who has control over my content, ultimately? That is, how easy is it to take all your content with you if you plan on leaving them in future?
2. Who has control over the design of your site? You may find that the template you use can't be taken with you if you leave.
3. Can you back-up your content automatically as often as you want (weekly, hourly, whatever you prefer) so that you have a current copy on your own computer?
4. What happens if you need a feature the service doesn't provide? Can you extend it?
5. Can you easily organize important areas of your site, like the navigation menu and the sidebar?
6. Does your website's design reflect how professional, credible and trustworthy you are? Or do you look like another cookie-cutter fly-by-night amateur because your site uses a run-of-the-mill design suitable for hobbyists?
I've helped people who were being held hostage by the systems they were using (not Blogger or WordPress, incidentally, but paid-for services that are actually rip-offs) and these considerations should never be taken lightly.