Ask your developers or whoever has access to your hosting provider’s site to add a CNAME (custom domain name) record to your site. This is a one-time setup for each subdomain. For example if you have www.buy.yourdomain.com for a landing page, and then you want to set up another one called www.sell.yourdomain.com, you’ll need a new record for each of those pages (one for “buy” and one for “sell”)
Unbounce also lets you create sticky bars for your site. These bright forms draw attention to the offers and help to get more conversions without paying for more traffic. The editor allows you to add pop-up windows (which are called overlays here) on exit, on arrival, after a delay, on a scroll, or on click. There are plenty of pop-up templates to choose from, and you may also customize them. This feature is not available with Instapage.