http://www.webdesignfromscratch.com/conversion-rate-optimisation/power-words/

You – It’s so simple, right? This word personally involves me and makes me part of the conversation. Use it early on in your copy.
Can – This tells me that this is something I can do.
Easy – Suggests that I won’t have to put in much effort to get what I want.
Get – Tells me I’m going to actually get something out of this conversation.
New – I’m going to be the first person to own it.
Exclusive – This thing is just for me – great!.
Exciting – If you say I’m excited, maybe I am excited.
Free – I don’t have to spend anything!
Gift – Something given to me for FREE? Yay!
Love – A word that will connects with me on an emotional level.
Delivered – It will arrive at my home safe and sound.
Direct – It’s coming straight to me, fast!
Immediately – I’m going to get this straight away!
Lifetime – Tells me that this is going to last.
Results – This is going to work for me.
Savings – I’m saving money by doing this.
Bargain – I’m getting something that is worth more than I’m paying.
How – Because people like to know the details.
Hurry – Creates urgency and tells me I need to act fast.
Offer – Suggests that this isn’t a permanent arrangement.