If you are using the article downloader or article creator it may be confusing as to why there is a Google search option and why there is custom sources, that have Google in the options again.
You may be wondering,
If I do not select a custom source (eg Ezine) and only choose a Google region (eg Google USA), will SCM only scrape Google USA?Why does it scrape Google + Google blog when only Google is selected?
How SCM looks for content
The program will only scrape content from sources that you enable.
In fact, you can select no sources at all the Article creator task will still run.
The reason for this is some people want to load in their own content.
If you are scraping content you have 2 choices:
1) Google search
All Google searches will return results from both search + blogs (about 150 links)
2) Custom sources
Under custom sources you have a couple of options again,
2a) Bing/BingCache/Google/Custom Search Engine.
Custom sources allows you to specify specific sites or your own search engines to find content.
How to verify what is happening
If you look in the application log, you can verify what sites and how many links are being found by the scraper.