Keyword research is the first foundation step for any website, seo strategy and even article marketing. Without doing keyword research, you are only assuming keywords you think people are searching in the search engines which may not be true.

Most people uses overture keyword inventory database to find out what people are searching for online because it's free. The other two keyword database are wordtracker and keyword discovery which are paid subscription.

Comparing the 3 keyword database

Let's take a look at how all 3 keyword database gather their database of keywords.

For overture, it is the collective keywords gathered by the yahoo and overture search engine and it tracks keywords up to 30 days.

One disadvantage of overture is the keyword search volume may not be always accurate as it can be skewed by automated bots hitting their search engines.

For wordtracker, it uses meta search engines such dogpile and metacrawler to gather its keyword database. It tracks keywords up to 90 days and it's keyword database has approximately 330 million keywords.

Wordtracker database is more accurate than overture as the chances of automated bots hitting meta search engines are pretty remote.

The disadvantage of wordtracker is that it does not accurate represent the internet's search volume keywords since meta search engines only takes up less than 1% of total keyword search volume.

For keyword discovery, it gathers data from more than 180 search engines with the majority from google. It tracks up to 365 days and has approximately 32 billion keywords in its database.

The major advantage of keyword discovery is in its massive keyword database which can allow you to dig up keywords that may not show up on overture and wordtracker.

Now you might think keyword discovery is the best keyword research tool since it has the largest keyword database. However it may not be necessary depending on what you want to do. For example, if you are just trying to come up with new ideas for a product or a website, then overture and wordtracker will be sufficient.

If you are trying to gather a large keyword list for your niche, then use keyword discovery. If you are doing ppc with adwords or yahoo search marketing, then developing a huge list of keywords is important and keyword discovery can do that better than wordtracker or overture.