Leveraging online advertising is pretty difficult, it's all about capturing and generating demand in your respective market. My advise to you would be to first look at a business development methodology called Customer Development. CD is a process of creating a product by first measuring demand, and allocating resources to bring that demand to life through development. Think of it like this, instead of creating the product first and trying to sell it, try the steps in reverse; which is to say, figure out the demand, then build the product once you have an established customer funnel which is repeatable and scalable.
Here are some resources:
Steve Blank - 30 years in Silicon Valley, formulated the basics of the Customer Development methodology.
Steve Blank Blog - Goes into a lot of war stories and anecdotes about how Customer Development came to being, the details of how it is flows, and some prime examples.
What is Customer Development
Other then that, I think your issue maybe that your copy just isn't converting necessary customers, and you just need to modify how you pitch.
Remember, hosting is a pretty saturated market, so web hosting itself may not be the best place to compete. Some people call these types of markets "red oceans," meaning everyone is in a race to the bottom trying to cutthroat the competition.
What you may want to do is go for a "blue ocean," in that you may want to attack a market that does not have a lot of other vendors, and where you can exploit the phenomenon of exponential growth and returns because of the markets relative immaturity.