Number of domains in HTTPArchive

If my Classified Ads Website is not in the top 1mill of alexa ranks I will not be able to see it on httparchive?

Correct, by default only the first 500,000 websites in Alexa’s top 1 million list are included.

HTTP Archive does have a way to add URLs that are not in the top 500k. Go to http://httparchive.org/addsite.php and enter your website’s URL to add it to future crawls. Be advised that this functionality may not work in the future beta site.