seo - why frames are bad -

I know that they are, but my colleague does not believe me, he keeps telling me that the content inside Google Carries and cache, it's okay. According to Google, it crawls them, but does not guarantee to do it properly.

Any ideas why the frame is bad for public web sites?

There are several usability and access problems with the frame:

1. Link Can open it in a frame in which it is attached (for example, a side pane
2. may break forward / backward navigation;
3. difficult to bookmark;
4. are not easily discoverable (there is a possibility to view content in Google, etc.)
5. Console / Terminal based; Browse such as Linux ;)
6. Difficult to properly size (like the consumption height on the widescreen monitor for banner frames);
7. Screen readers and magnifiers (blind users and view impaired users) For example)

For an example of not doing this, see.