Internet is full of opportunities, especially if you're in web design and development business. Everyone needs a website, and plenty of people don't know how to make it. That's when those who know how to do it often get started with their business of building sites for others. It can be a cosy job - you can do it from home, without boss, and be well paid if you have good clients, but also, it can be a stressful job - clients that don't know what they want, but always ask for changes while building site, tight deadlines and unslept nights of work. As many jobs, it has it's upsides and downsides. But the bottom line, in most cases, is - you get paid for the project once, and that's it. It's basically an earned income - active income.
Most of web designers and developers have to be good at that field anyway, to make good sites for their clients, but, they're probably unaware of the way they can use their talents to make residual, long-term online income. The business of internet marketing involves site building, and it can be a real bonus if you're professional in it, but is focuses around giving reasons for site's visitors to want to know more and eventually buy products, if you're in affiliate marketing, which is the easiest internet marketing segment to reach into.
Affiliate marketing is a business you'll enjoy doing once get into it, because it allows you to easily merge your favorite hobbies and passions with earning money. Main story of success behind it is quite simple; choose a niche you love and enjoy working with, build up a site about that niche, or a product within it, then learn to promote the site to get traffic and earn from commissions when visitors opt in from your affiliate link.
For example, if you enjoy photography, you can start a website talking about something related to photography - you'll have to choose a niche that has enough demand by surfers and low competition. Then write and/or let others write for the site and create enough ideal content. Put your affiliate links and affiliate products on your site, also related to the topic you'll work with. Then get free traffic from link building, article marketing, or search engine optimization. You'll get surprised with the financial potential of this type of work. If your site has good enough conversion rate, you can profit a lot from just 100 visitors a day. You can easily replicate the process with other niches. The more successful sites you'll have, the better of your bank account will get.
Among all the reasons to get in the internet marketing, or joining valuable affiliate marketing communities, is that it's a permanent residual income opportunity, meaning, your links remain online always, so there will always be a chance that someone opts in from them.
You'll find plent of reasons to do this type of job along the way, but at least learning more about it is a good step, to get another benefit from your web development talent.