I am wondering if i should use the keyword "free" in front of my primary keyword to drive in traffic, although i don't sell my services for free. I offer users 1 or 2 free trials, but after that the services are charged. When i removed free from my keyword my traffic started to drop so much that i am thinking of adding it back again, but confused thinking about google penalty, conversion rates and bounce rates. Can some one advice me.
The word free is very competitive if you put it in front of your keyword it would not necessarily drive more traffic. If you are selling apples and your keyword is "apple for sale" for example putting the "free" keyword in front will create a completely different keyword with different competition "free apple for sale", meaning that you will get into a very competitive niche of freebie sites, who have multiple different high quality back links for keywords similar to the one above.