Alcuni utili keyword tool (alcuni includono anche il trend):

http://www.google.com/sktool/
http://www.google.com/insights/search/
https://freekeywords.wordtracker.com/
http://www.keyworddiscovery.com/
http://www.wordstream.com/keywords
http://www.keywordcountry.com/free-keyword-tool/

Un elenco molto completo di servizi per l'analisi competitiva:

http://tools.seobook.com/competitive-research-tools/