This won't be a problem for you if your blog is running on your company web server, managed by the IT department. However, many readers will have installed their self-hosted WordPress blog on a shared hosting account. This means it's on a web server alongside lots of other people's websites, all of which have to share the server's resources, such as memory (RAM) and processing power.
Shared hosting accounts have limits set on disk space and bandwidth. As the traffic volume to your blog increases, you may well start to exceed these limits. You may also experience performance issues (remember you're sharing memory and processor with lots of other websites). There may well come a time when your blog simply outgrows its shared hosting space, and you have to think about upgrading. If this happens, you need to...