Wordtracker searches per month, competition, kei, kei3

I found a keyword on wordtracker that gets 550,000 google searches a month. 3,300 competitors with the keyword in their page title and anchor text to their page. KEI of 13,600,000 and KEI3 of 167.

I just want to know if this keyword would be worth investing in If I was planning to use Xrumer? Please state your opinions please. If this would not be a good keyword to target please let me know what numbers I should look for.