When starting a new site, it can be difficult to find some initial users and gather feedbacks for a small site with limited budget.
Stumbleupon.com can be a good place to start some advertising and testing on the broad market. If you haven't tried StumbleUpon yet, it's a website that categorizes a big pool of websites and pages and show them to websurfers. A user can setup an account and select the categories that interest him and stumble away by clicking on the StumbleUpon toolbar on the browser.
To advertise on it, you can create an account and add the URL that you want to be included in its big repository. You can select the category and also customize who you want to show to by selecting the gender, age and geographic location of your visitors through StumbleUpon. Each showing will cost $0.05, and you can put a daily budget by limiting the showing number and max spending.
Once your ad has been approved, you should start seeing the report about how the StumbleUpon visitors think your website. Unfortunately right now there are only 3 opinions, like, dislike, or neutral.
What I like about it:
I believe the StumbleUpon users are early adopter of new things on the web. So they are more likely to viral marketing for you if your site is really a hit. Plus and your visitors are those who are interested in the subject so they are more likely to be your targeted visitors in the first place.
Although most of the stumblers choose not to rate (at least in my ad experience), you can still get some feeling about the acceptance of your site. Granted, if most of your feedbacks are negative, there is definitely something you want to look into.
How can StumbleUpon improve the system:
If StumbleUpon can encourage the stumblers to rate more and even add some comments besides like or dislike, it will be a hugh help for advertisers. I would even create some power user groups system and pay them for rating and commenting (Well, this may be already in place under the cover). This would attract more advertisers since the system essentially offers a focus group to the web designers. And if you can get a thumb up/down and a small comment for 5 cents, it's a pretty good deal.