BrewAdvice has the clear advantage over all the other sites in the arena of direct question & answer. Homebrewers are a great bunch of people; willing and wanting to share their opinions, ideas and designs. However, because the software does not have other features, such as recipe sharing or friending, it will likely always be a small player.
Obviously, I like the site. I have put a lot of my time into it. In order of least liked to most liked, here are my opinions. My suggestion is to find a combination of revenue streams.
Advertising
Sufficient advertising revenue is directly dependent on the number of users & quality of ads. Can we reach a point funded solely by ads before the founders run out of spare cash? I use ad-block+, a firefox add-on, so I usually don't see the advertising.
Affiliate
This has the potential to get more revenue than passive ads. It will be more work since we have to find a way to drive users through to the affiliate site. One way to do this would be to post-process questions & answers for keywords (like keg and chiller) and forcibly link them to the affiliate site. I'm loathe to suggest it, but it could be quite powerful.
Donations
This has worked for the Homebrew Digest since about the dawn of time (Oct '88). Their expenses are likely much lower than ours - it is an email list and some 1980's-looking web sites.
DIY
Cheapest, cash-wise. Most expensive, time-wise. I know the founders are a couple of capable young guys. StackExchange is a great platform and we, as users, would have to put up with a less featureful site while PJ & Taylor build something from the ground up. It did not take much time for BrewAdvice to hit a sufficient number of users that they were happy to turn over "control" to us, so once the two of them (with help from others here) get a working site BA will quickly be back to full-strength.
Sponsorship
$1600 a year is a small amount for any large homebrew shop or brewery. There is already good content here, making the pitch to potential donors easier. B3 and Northern Brewer have sponsored the Brewing Network and would be my first place to look. Many microbreweries consider themselves "teaching" breweries and would be open to fostering beer knowledge growth. Get a good pitch, show them what we are doing for the community and the money will come.
Partner
It's been said before: BredAdvice lacks some features to make it a one-stop-shop for brewing information. By partnering or integrating with other sites, like the recipe-sharing site HopVille (and makers of BeerCalculus) or a "real" wiki like BrewWiki, those shortfalls can be overcome. With more to offer, users will come back (and click on your ads).