KeywordSpy is appropriate for most Internet Market research companies. I would not suggest it for a corporate marketing department unless it's a company with a very larger budget. This is also not a tool for small freelancers even though there is a free option, to get the best benefit of KeywordSpy it's best to use most of its features and options and this can get pricey.
As I am a content marketer, every day I have to fight to get top-ranked for my articles. So, SEO should be perfect. For my content side of SEO, MarketMuse is a lifesaver to me. It helps me to plan my content, get the score of my content, and the suggestion to optimize my articles. It saves my time and money too.
The support I have received from all MarketMuse staff at each step of the process has been excellent. They are very friendly, quick to assist, and also provide really good training to teach you how to use their product. Additionally, their own blog is a wealth of information regarding different aspects of content marketing, from articles to video interviews.
Most SEO and market research tools offer what KeywordSpy has but are not as detailed and in one place. Consequently, where you can do everything at KeywordSpy, with other tools you find you have to purchase multiple tools or subscriptions from different providers which also don't integrate with each other. KeywordSpy makes your research easier and more efficient.
MarketMuse is more cost-effective than BrightEdge and does more for writers and editors that are strictly focused on content. It keeps people in one system after their first draft. Writers and editors do not need to go into multiple tools to look things up manually, saving valuable time. This enables them to produce more content more quickly.