Buying traffic from Text Link Ads

I was looking at Text Link Ads earlier today, I thought maybe I would buy traffic from them. They seem to have a great program and some really good sites where I can get a 30-day link pretty cheap. I found a few good ones, and the price was $20 and $30 for a month. So why not? But when I looked closer at the sites that they offered, there were no links to them. I couldn´t see the sites for myself. I could only see their alexa ranking and their popularity and how many sites my ad would be on. This is not good enough for me. I have to visit the actual site before I buy an ad. How else can I know that the site is any good, and how else would I know where my ad will appear (bottom, top, left, right). And I am not sure if I trust them enough to pay money, even though it´s only a few dollars, for an ad that might not be displayed at all. What happens if I get accepted to the Text Link Ads program and after a few weeks (or months) decides to remove their ads from my site? Will my site be removed from their program immediately? So nobody can by ads for my site, or will it be hours, days, weeks, months before my site will be removed from their directory?