honestly do not believe its accurate at all. First off i would think internet usage has drastically increased since 2005 yet in google trends almost all keywords are in a decline since 2004. Then on the google adwords calculator the results don't match some times. Here is an example if i use the word "widgets1" and "widgets2" and compare them using both adwords tool and the google trends the results are exactly the opposite widgets1 is higher by far using google adwords keyword tool, then if i use google trends widgets2 is higher???
It is true that Internet usage is up, but it is also true that less people are searching on Google. I've heard some of the reasons include dissatisfaction with SERP results. Did you know that search strings are getting longer and longer? It's because more and more say they can't find what they are looking for in Google. Another cause for declining Google searches is social media sites like Facebook and others, and also adult sites. This is where most people are headed, not Google.
What is not accurate for a fact is the google keyword tool, they heavily overestimate search volume...
yes it is correct bro,i would say it is 100% correct! To verify yourself just check the trend in Friday you will definitely find one of the keywords referring to movie released on that day or you can also check it on any festival you will amazed what peoples are searching.
for websites it shows some good results for highly trafficed websites, but google sites are filtered there
It is as accurate as any other tool. You just can't rely on one. I use two, or three when doing my niche finding. Most give me the same results.
The market share for Google is about the same as it's always been. If the number of users has gone up then the number of Google users has also gone up. All the market share services show Google's share has not changed or gone down. So that statement is false. Facebook, and those other sites, are not search engines.
Google trends tool is vet inaccurate. I do not not what is their algorithm, but for some keywords that are on the first of google page I sometimes get much more traffic, for other keywords even in if it is 1-3 result, I never get even close to what Google Adwords tools says. Google trends is the same, but it is very good to use it to identify current hot topics.