Your sales copy could be weak, in addition to not having a platform to follow up with prospects, everything has to be in place prior to a successful Adwords campaign mhclysmic
I've also failed in the past. Where can I get Google ad credit? I want to test run my campaigns too. Sounds like a great and cost effective idea!
Good content in articles helps to drive people to your page...if the ads are enticing then you'll get a few clicks
A really good thing i do is use a program called keyword spy. I'm not an affiliate for it, so i will not place a link here, but its a great program. Tells you what keywords your competitors are bidding on, how much they spend, what their position is, all very quickly. Another suggestion I would make is use a small budget when testing an offer. I usually spend about how much the offer pays in ppc, so if its a cpa offer that pays $40, I'll spend $40 in adwords. IF it doesnt convert, I move onto the next one. You will see that about 1 in every 10 campaigns is a winner. IT sucks forking over the initial $400, but you end up making that back monthly, sometimes more, and you can basically automate the process. Use common misspellings too, very few ppc'ers do this.
Maybe I'm a little different but I have always thought that Adwords and PPC be left to the experts. PPC charges for what SEO provides free of charge but just takes longer to administer. SEO is more or less free to learn as you apply and by the time you've got to where you want to be you may not need PPC. Websites are supposed to be informative and helpful and if they are they will get discovered using good SEO. If your website is just spammy or is just another mirror site then there is no more reason for them to buy just because you've paid for the click. Learn SEO and apply it on and off-page and then, if you must, run a very small PPC campaign to get the ball rolling and people will bookmark you page if it is good enough. I like to look at SEO as Sensible Educational Opportunity as well and it has always worked for me.