Designing Call-to-Action Buttons that Customers Click
Place the CTAs prominently
Fitt’s law explains the visual hierarchy in human-computer interactions. For example, it’s common for good interfaces to group items together when they are related, as it makes browsing and clicking actions easier for users. Marketo ran a test to determine the best CTA placement emails. In this subtle but effective test, they found that the left-aligned CTA button version had 90 more clicks than the center-aligned CTA button. They determined that these results had a 95% confidence score, making the left-aligned CTA button a clear winner.
Create urgency in the minds of visitors
Creating urgency is a time-tested approach that delivers results. By including additional button text, like “Limited time offer”, “40% holiday season discount” and others, you compel visitors to take action quickly. Otherwise, they will have a sense of loss. This CTA button is effective, motivating customers to make online purchases fast. 
Use colors in CTA buttons to stand out
If you want a design element to stick out, you can choose a color that is complementary to the background. For large buttons, select a color that is less prominent in relation to the background and for smaller buttons opt for brighter colors. Whatever colors you decide, design the buttons to get noticed without interfering with the rest of the page design.
The three best colors for call to action buttons:
1. Red: The color red stands out on most web pages. It also signals urgency.
2. Green: If the product or service you are selling relates to the environment, psychology, and peace of mind, then green is the right CTA button color for you. In addition, green is calming and can be associated with “Go”—a motivator for many customers.
3. Orange or Yellow: Orange is exciting and warm. This color leads to visitors to take action. Amazon uses yellow and orange through their site. They do a lot of website optimization testing, so it is likely these colors will work for your website too.
