E-Commerce & Payments
Selling Things on Your Site (E-Commerce)
If you want to run a store on your website, there are a wide variety of e-commerce solutions to look for.
There are a number of WordPress e-commerce plugins such as free WP E-Commerce, WooCommerce and many more at CodeCanyon. These let you run an entire shopping site within WordPress.
If you wish to run your store in an outside network, consider Shopify and link to it or use their plugin to embed your shop within your WordPress site. If you’re in handmade crafts or vintage objects, you might look at Etsy and the Etsy Pro WordPress plugin.
Collecting Online Payments
If you want to collect money from people via your website, there are a number of free and inexpensive tools for this:
Read about other payment alternatives here: Why You Should Ditch PayPal and Use These Other Services to Send People Money (Lifehacker)
If you want to integrate payments and subscriptions more deeply into a custom website, check out Stripe and its WordPress plugins for Stripe.
Many of these services also help you accept credit cards in the real world, such as SquareUp (not to be confused with SquareSpace).
