I am quite a fan of Google trends; not only does it get updated regularly, and provides some very useful and interesting data.
I wanted to check on the trend over the years for some of the typical SEO terms.
There weren’t really too many surprises there but here goes:-
Anchor texts
It still is a popular term and holds importance, and in my opinion it will continue to have some level of interest

Content optimization
It is a very important element of SEO, and shows a steady trend

Directory submission
This shows a downward trend, and it is not a surprise.

Internet marketing
Shows a downward trend too!

Keyword optimization
Downward trend!

Keywords
Has gone down over the years but is still important

Link popularity
Not so popular anymore!

(The graphs/ data above have been collected from Google trends)
To be continued….