Hope you are eager to get traffic from USA. What you have to do is just make Search of keywords trend in USA. Target those keywords and start working on them, once you achieve top most position for those keywords you are sure to receive traffic from USA and that too from Organic Search which is considered to hold high conversion ratio.
I can kindly offer you high volumes of US traffic, you can check out my sig if it's of any interest for you
US traffic if you want to buy than it cost more than any other country, but still you could check CPV advertising option, which shows ads in full page pop window, and you get 1000 valid unique visitor in $4-5 if you have something good to offer and your landing page is interesting than you could utilize it good
I have a classified ads website. is it really important to have a US based webhost? What if I just promote it to social bookmarks, directories and do link building? will this work?
you must have .com domain if u want usa base visitors in your site then make some submission in us/canada/uk web directories " web-directories.ws/Regional use this site your site definitely will get visitor which u need for your site thanx regard
Use the google keyword tool to and fix up of the kw which has good search volumes in the United States, submit the site to US based directories, forums, classifieds. Do blog comments on blogs from US. This will ensure that your site shows up on SERP's for relevant kw's and thus ensuring increased traffic.