WordStream for PPC is a full-service PPC management platform for creating, optimizing and managing pay-per-click advertising campaigns in Google AdWords. Our PPC software includes easy-to-use PPC keyword tools, campaign creation and expansion tools, Quality Score optimization tools, and more to help marketers get their PPC work done quickly and cost-effectively. WordStream for PPC customers experience increased traffic and greater ROI.
But it’s still very useful for getting search volume data (provided your account still shows this), which is helpful when choosing which of the many keywords you’ve found to focus on (although you should take these estimates with a pinch of salt, they are still useful in indicating the relative search volumes of different keywords, even if the absolute estimates are a little off).
This makes Google Suggest a relevant source for keyword research, it contains a large amount of organic keywords very closely related to a full or partial keyword and can be used to find additional most searched appending keywords that make the whole keyword less competitive. Google Suggest can be researched through the Google Search website or through a compatible browser for a small amount of keywords but also in large scale using free scraper tools.
Long Tail Pro is a keyword research tool that helps you quickly find low competition keywords for your website. In particular, the tool is built for people doing SEO (search engine optimization) as opposed to people doing paid ads (Google Adwords PPC). I'm sure there are some advertisers that use the tool for paid ad keyword research, but the tool was built for SEO keyword research.