05-16-2013, 01:59 AM
You should immediately place the Google Analytics code on any website. As that will get you data. That's immediate and is super important to metrics.
Now, if you are asking once you make changes, how quickly will Google recognize them, you are really asking the question of how to get Google to reindex your website.
This is always a common question. The answer is of course 'it depends.' You have to think like Google. If Google is spidering your website, and it finds that you change the home page and site itself very infrequently (e.g., once per year), then it is smart enough to figure out NOT to return except once per year. Then, if you start improving your on page SEO, it might take ONE YEAR for it to notice the changes.
Alternatively, if you change your site frequently - blog, create news, issue new content, change the home page content - say, once per week... Google realizes that you change WEEKLY and returns WEEKLY. In that case, you can make changes and get them on Google within one week. Syndicating news is so important here - because syndication creates buzz on social media (Twitter), new links (reposting on Blogs), etc. So issuing a news release is my #1 recommendation for most websites.
So, to get it to reindex, change your reputation via LINKS - NEWS, etc.