How come i always have to update my keywords??

[rsalan]

How come i always have to update my keywords??
and do i also have to update my meta descriptions??

[mshah]

because your competitors are always updating theirs.

SEO is not a one time action where you set it and walk away.

updating your description is part of out ranking your competitors

[irahat]

Next time they crawl your pages, if you have modified the pages, they will notice that your pages have changed and they will slurp the contents.

They will look for a If-Modified-Since field to compare the time since last accessed. If they don't get a 304 status code, then they will 'take' the pages afresh.