A '''call to action''', or '''CTA''', is a banner, button, or some type of graphic or text on a website meant to prompt a user to click it and continue down a [[conversion funnel]].<ref>{{cite web|last=Yerian|first=Nathan|title=Give Your Sales Team the Gift That Keeps On Giving|url=http://www.adherecreative.com/blog/bid/109530/Give-Your-Sales-Team-the-Gift-That-Keeps-On-Giving|publisher=Adhere Creative|accessdate=26 January 2012}}</ref> It is an essential part of [[inbound marketing]] as well as [[permission marketing]] in that it actively strives to convert a user into a lead<ref>{{cite web|title=Strong Call to Action - Convert Website Visitors into Leads|url=http://www.hubspot.com/internet-marketing-tips/lead-conversion/|publisher=Hubspot}}</ref> and later into a customer. The main goal of a CTA is a click, or a scan in the case of a [[qr code]], and its success can be measured via a conversion rate formula that calculates the number of clicks over the times the CTA was seen. Another way to test the effectiveness of assssssssssssssssssssssssssssssssssssssssss CTA is using [[A/B testing]] where several graphics are presented to a user and the graphic with highest success rate becomes the default.