In this tutorial we show you what theme customization is from a user’s perspective. We also walk you through using the WordPress Theme Customization API.
Good basic tutorial for understanding Theme Customizer concept, including Sections, Settings and Controls.
Source: Getting Started with the WordPress Theme Customization API
People ask the question a lot – should they charge annual or monthly subscription fees. Here’s my take.
Chris recommend annual. Couldn’t agree more.
Source: Should I charge annual Subscription Fees? Or monthly?