Many sites ( businesses) have a 1 - 2 % conversion rate.. In that case 100 clicks is not enough to get a judgement on effectiveness. A 1000 clciks will give a better idea. Depends totally upon your product / industry average.
Think in terms of a bricks and mortar business. Lots of people will respond to an ad and take a look at the store, its down to your products, you pricing and your shop layout to make them want to come in and buy.
The trouble with CPC advertising is that you are paying for each person who just "looks through the window" so you feel upset when they shrug their shoulders and walk away.
Try turning off serving the ads to anywhere other than Google, i.e. don't show ads via adsense. There's a lot of nasty stuff on the adsense channels, you should investigate that seperately and after you know what you're doing.
You can "buy the love" or you can have a business that sometimes attempts to "buy the love"... there are no guarantees... and advertising is expensive no matter how you look at it. Cost of doing business. If playing that game, one needs the MOST HIGHLY TARGETED AND SUCCINCT ads to make it worthwhile. In most cases a 10% return is general in this type of advertising, thus balance between cost and return (ROI) is imperative. Do the homework first, else listen to the vast sucking sound as funds disappear...
Echoing what Marshall and others said, maybe you are too generic with the keywords you are using. Also, people land on your page and don't find your offer attractive enough. 100 clicks is not enough, not when most report conversion rates of 1-2%. But with a good sales letter, that can be 5% and more, even 10% is possible.
Remember that PPC can only bring you quality visitors, if you do things right. It does not guarantee sales. That's your job. Actually, it's both your jobs, attracting quality visitors using PPC and then selling to them. I've seen very few do both well and many can't even do one of them well.
I am NOT an adwords expert by any stretch of the imagination, but make sure that you are using the right "match" for your keywords.
As an example, you PROBABLY would want to make sure that you are using exact match for your keywords, but by default, Adwords sets your keywords to broad match, whcih can get a lot of irrelevant clicks that will just cost you time and money.
I was one of GoTo.com's first customers - in Jan 2010, I handed all the PPC stuff to an AW Certified Consultant. He studied my product line, and has been able to come up with a good list of negative keywords, a good list of correct keywords to bid on, the proper positions of my ads.
The landing pages are up to me, and we're constantly fine-tuning, testing, fine-tuning again.
All of this PPC stuff is probably easy if that's what you do all day long. Me? I sell stuff on my site all day long. I don't have the time to manage a couple of dozen or so different types of widgets for sale.
He charges me 15% of my ad spend. Smartest money I've ever spent.
mike that is misleading and incorrect information. 100 visits doesnt gaurantee a sale, even if the products are great and the prices are good.
AS said above, most ecommerce sites hover around 1-3% conversion rate. But, you need more than 100 visitors to gain an accurate assessment of whether the campaign is working or not. The reason a sale was not made is because none of the 100 people chose to buy this time. But, it DOESN'T mean there is anything wrong with the campaigns OR the site (though these could both be possibilities).
As Green Grass aid above, you need higher figures over a longer period before you can make ANY assumptions on this campign, or the site.
As another possibility, were any of your ads at the top of the page above the organic results? It is possible that people are mistaking them as an organic result owing to the new light background of the ads.
I've never been successful with Adwords. At best I've just broken even, with the cost of the ads roughly equaling the profit on the items sold. There's no doubt something with my site that is causing people to not complete the sale. So, take what I have to say with a spoon of salt.
I found myself advertising for "Acme Widgets", and getting a lot of clicks from tire-kickers. These were people who had heard about Acme Widgets, and wanted to learn more.
I decided to narrow things down, as in a lot. I changed the ads to "Acme model 114C Widget", so that I would get the person who already knew about Acme Widgets, and knew what he wanted. No tire kickers.
To narrow things further, I put the price in my ads. "Acme model 114C Widget, $14.95 Out The Door". Now people knew m prices, so they should only be clicking if they're interested in the model 114C at $14.95.
The fact that those clicking on the ad aren't buying tells me that there's something about my site that's turning them away.