If you're looking to monetize your website, be it a blog or a site hosting user created content, you might want to give one of these Bitcoin-based ad networks a go. Bitcoin based networks allow you to withdraw your payouts much more frequently (in the best case as often as every 24 hours) and may give you more control what kind of ads are displayed on your site.
Ad networks vary a lot on different features: what kinds of ad formats they feature, what requirements they have for websites and how they calculate a publisher's earnings (CPC as in cost per click or CPM as in cost per impression). Since no two sites are alike, you may earn more or see better ads on one ad network than the other. For the best results give a few of these sites a try and see which one works the best for you.
List updated on 1.5.2016.
Payment method: CPM, CPC
Payout frequency: ~24 hours (manual approval)
Adalso is an ad network where advertisers can directly bid and advertise on your site, paying either by per impression or per click. Network ads are run on ad units which don't have active bids.
Payment method: Pay-per-day
Payout frequency: ~24 hours (manual approval)
AdBit is an ad network using the pay-per-day system, where advertisers directly bid on different ad units on your site. AdBit has also recently added a Network Campaigns feature that allows network ads to be displayed on ad units with no active bids, allowing a more steady income in case of infrequent advertisers.
Payment method: CPM, CPC
Payout frequency: ~24 hours (manual approval)
Site requirements: at least 100,000 monthly impressions
Adverti is an ad network that pays the publisher in both bitcoins and USD. And unlike most other networks, they serve ads from multiple different ad networks such as Google's DoubleClick, usually resulting in more fitting ads if your site's niche is not related to Bitcoin.
Anonymous Ads
https://a-ads.com
Payment method: CPM, CPC
Payout frequency: ~24 hours (automatic)
Anonymous Ads is one of the longest running ad networks in the Bitcoin space, and it remains the easiest to setup: just create an ad unit with your site's address and a Bitcoin address for your payments and you're ready to go; no registration required. Bitcoins are sent automatically to your bitcoin address once you have earned enough for a payout.
Payment method: CPC
Payout frequency: ~24 hours (automatic)
BitClix allows advertisers to advertise directly on sites of their choice. Publishers are paid on the amount of clicks their ad units receive.
Payment method: CPC
Payout frequency: ~24 hours (automatic)
Site requirements: site approved manually
BitMedia is a Bitcoin ad network with strict requirements. New publishers are recommended to include site analytics when filling the application.
Payment method: CPM
Payout frequency: Once a week (manual)
BlockAdz is a fairly new site in the scene and unlike different ad networks your earnings depend solely on the amount of impressions your ad units receive.
Payment method: CPM
Payout frequency: Once a week (manual)
Site requirements: At least 100,000 daily impressions, Alexa rank <100,000
CoinAd is run by the same owner and uses the same payout model as BlockAdz, but has far stricter requirements when it comes to publisher sites.
Payment method: CPC
Payout frequency: Once a week (manual)
Like Anonymous Ads, CoinURL is one of the longest standing Bitcoin ad networks. CoinURL's ads pay solely on amount of clicks your ad units receive.
Mellow Ads
https://mellowads.com
Payment method: CPM, CPC
Payout frequency: ~24 hours (automatic)
Site requirements: Alexa rank <1,000,000
Mellow Ads serves network ads and pay based on both impressions and clicks. Earnings in your balance can be withdrawn at any time.
Payment method: CPC, CPM
Payout frequency: ~24 hours (manual approval)
U-Ads is a newcomer in the scene, having been launched only two months ago when this post was first written. Ads served by U-Ads pay for both impressions and clicks.