Keyword research has evolved quite a bit over the years. Some tools have come and gone and some have been around for a long time. These are some of the best:
This is one of the long-time great performers. The data is first rate. Basically, they are scraping Google – it would seem. You can see PPC stats on any site. You can check rankings. You can investigate your competitors.
There are some great ways to use this tool. It’s’ a great way to assess what you are doing well in and investigate what you could be doing better in. Under “Organic Research”, click “Positions”. You can see terms that you aren’t doing so well on and work on optimizing for those terms. Great use.
You can also use SEM Rush to get your competitors’ domains and find the keywords they are optimizing for.
This basically appears to scrape Google Suggest. It’s a good way to identify long-tail terms.
This is a really great long tail keyword finder.
This tool provides you with Keyword Strength values from Majestic, as well as unique linking IPs for top 10 results.
This one has been around forever. And, it’s still golden. It will basically give you the PPC campaigns and the organic keywords of you competition. You can assess a competitor’s keyword bidding. You can also see ad copy.
This is one of the best and oldest in this niche. While a bit costly ($79/month), it is very reliable. You can get all of your competitors’ profitable PPC and SEO keywords. You can also see the various ad variations of competitors over time and their rankings history over time.