http://www.esearchclick.com
20 % of Internet marketer makes less than $30,000 a year as an Internet marketer. Companies are spending at least $73,241,464 a month on PPC ads.
SEM tools are used by most of the companies and these tools are effective in improving marketing results.
The most useful SEM tools:
Wordtracker
Keyword discovery
Spyfu
Keycompete
Wordze
Hitwise
Compete Search Analytics