I'm the publisher/editor of one of the magazines that Nancy mentioned. I've been doing this for six years now and would be more than happy to share our experiences. Any 80% failure rate seems low for an digital publication. The bar to entry is quite low, so you have a lot of people who jump in not really knowing what to expect. (many rude awakenings) The work actually gets easier as you develop a routine that works for you. The more successful ventures are willing to invest in their business, pay contributors, etc. It does impact the quality of your publication and your ability to successfully market it. Making money at this is fairly difficult and takes a while to happen, if ever.
Personally, I think that it is better to publish monthly or even more frequently. Any longer is a digital eternity and you'll be more likely to be forgotten. Stagger the contents of an issue across a quarter if you have to. At least there will be new content available and that's the only reason someone will come back.
The killer for most people (at least in the SF/F world) is generating income. Advertising is not going to amount to much and a new publication doesn't have enough of an audience to make it worthwhile to an advertiser. Donations or kickstarter are certainly ways to start, but over time you'll start to see donor fatigue. It's not really a business model. (Ok, if you are lucky you find a wealthy patron.)
The best source of income for a digital magazine is ebook editions, preferably esubscriptions. Again, frequency plays into you bottom line and subscriptions improve convenience (with is the most important thing you need to work on). The problem here is that it isn't easy to get into most of the major subscription outlets. Amazon, for example, is currently closed to new magazines. B&N won't return emails and others, well, they'll tell you they can't do it yet. Some sell direct, others find places like Weightless Books who will sell subscriptions for them.