If you have an engaging community and hold a lot of expertise within your niche, you can host private webinars that require payment to be a part of. There's loads of software that you can use to do this, both free and paid.

Some examples of paid platforms are MegaMeeting, Adobe Connect, Cisco WebEx and Infinite Webinars. If you want to go with a free solution then you could use Skype or Google+ Hangouts.

Advantages: Not only is this a good way to make money from your blog, but it's also a great way to build a solid online community. Over time, as you establish your presence online, you can really charge a premium for these kinds of webinars and when you get a lot of people signing up, you can earn some serious cash.

Some blogs offer webinar subscriptions as well, which means that you will bring in yearly/monthly/weekly retainer income, which is great for long-term growth.

Disadvantages: If you're offering premium webinars, you really need to be offering some very valuable information. Not only this but there's a lot of work involved in hosting and promoting webinars.

If you're putting the hours in to get some really valuable content together, the last thing you want is to have no uptake on the premium webinar and a waste of your time/money.