Journal publishers that want their articles to show up in relevant abstracting and indexing databases must submit article information to them in machine-readable formats. If you only publish journal articles in human-readable formats, like PDFs, you're likely missing out on valuable indexing opportunities.
Now if you use Scholastica Open Access Publishing, and your journal is listed in the Directory of Open Access Journals (DOAJ), you can have all of your articles automatically deposited into the index - get the details!