Presented at CodeMash 2015:
I’ve been playing around with a Spark Core, which is a small, cheap ($39) Wifi-enabled Arduino-compatible device. As a software guy, I don’t do much with hardware, but the Spark Core makes it really easy to get going.
The whole setup is pretty simple, and I’ve put all the relevant firmware and software up on Github in case anyone else is interested in doing something similar. Total hardware cost was $42, and just $1/month for Twilio.
I run advertising on several of my websites, mostly through Google AdSense. My sites are free communities that don’t otherwise sell products, so advertising is the main way I cover operational expenses. AdSense has been a great partner over the years and the ads they serve aren’t too obtrusive.
However, I realize that many people see all advertising as annoying, and some run ad-blockers in their browser to filter out ads. AdBlock Plus and others are becoming more popular every year.
Since advertising is such an important part of my business, I wanted to try to quantify what percentage of ads were being hidden by my visitor’s ad-blockers. I did a bit of testing to determine how to detect if my ads were being blocked, then ran an experiment on two of my sites. The first site, with a travel focus, saw approximately 9.4% of ads being blocked by visitors. The second site, with a gaming focus, had over 26% of ads blocked. The industry average is around 23%.
While the ad-block rates are fairly high, I’m honestly not upset or surprised by the results. Generally, people that have an ad-blocker installed won’t be the kind of audience that is likely to click on an ad. In fact, I often run an ad-blocker myself. However, knowing which visitors have blocked the ads gives me an important metric to track in my analytics. It also offers me the opportunity to give one last plea to the visitor by subtly asking them to support the site via donations if they visit often.
What I don’t want to do is annoy any visitors that are using ad-blockers with my plea, but I do think there’s an opportunity, if you’re respectful with your request, to gently suggest to the visitor an alternate method of supporting the site. Below are screenshots of what sarna.net looks like if you visit with an ad-blocker installed.
Zoomed in, you can see I provide the visitor alternate means of supporting the site, as well as a way to disable the message for 100 days if they find it annoying:
Since this prompt is text-only and a muted color, I feel that it is an unobtrusive, respectful way of reaching out to the visitor. So far, I haven’t had any complaints about the new prompt — and I’ve had a few donations as well. A very small percentage click on the “hide this message…” link.
The logic to detect ad-blocking is fairly straightforward, though there are a few caveats when detecting cross-browser. Other sites might find it useful, so I’ve packaged it up into a new module called adblock-detector.js. I’ve only tested it in a limited environment (IE, Chrome and Firefox with AdBlock Plus), so I’m looking for help from others that can test other browsers, browser versions, ad-blockers and ad publishers.
You can use adblock-detector.js to collect metrics on your ad-block rate, or to appeal to your visitors as I’m doing. I provide examples for both in the repository.
Please use the knowledge gained for good (eg. analytics, subtle prompts), not evil (eg. more ads).
If you want a fully-baked solution, I would also recommend PageFair, which can help you track your ad-block rate, and more.
adblock-detector.js is free, open-source, and available on Github
Several years ago I wrote a small tool called ChecksumVerifier. It maintains a database of files and their checksums, and helps you verify that the files have not changed. I use it on my external hard drive backups to validate that the files are not being corrupted due to bitrot or other disk corruption. At the time I created it, there were several other simple and commercial Windows apps that would do the same thing, but nothing was free and command-line based. I’ve been meaning to clean it up so I could open-source it, which I finally had the time to do last weekend.
A checksum is a small sequence of 20-200 characters (depending on the specific algorithm used) that is calculated by reading the input file and applying a mathematical algorithm to its contents. Even a file as large as 1TB will only have a small 20-200 character checksum, so checksums are an efficient way of saving the file’s state without saving it’s entire contents. ChecksumVerifier uses the MD5, SHA-1, SHA-256 and SHA-512 algorithms, which are generally collision resistant enough for validating the integrity of file contents.
One example usage of ChecksumVerifier is to verify the integrity of external hard drive backups. After saving files to an external disk, you can run
ChecksumVerifier -update to calculate the checksums of all of the files on the external disk. At a later date, if you want to validate that the files on the disk have not been added, removed or changed, you can run
ChecksumVerifier -verify and it will re-calculate all of the disks’ checksums and compare them to the original database to see if any files have been changed in any way.
ChecksumVerifier is pretty flexible and has several command line options:
Usage: ChecksumVerifier.exe [-update | -verify] -db [xml file] [options] actions: -update: Update checksum database -verify: Verify checksum database required: -db [xml file] XML database file options: -match [match] Files to match (glob pattern such as * or *.jpg or ??.foo) (default: *) -exclude [match] Files to exclude (glob pattern such as * or *.jpg or ??.foo) (default: empty) -basePath [path] Base path for matching (default: current directory) -r, -recurse Recurse (directories only, default: off) path storage options: -relativePath Relative path (default) -fullPath Full path -fullPathNodrive Full path - no drive letter checksum options: -md5 MD5 (default) -sha1 SHA-1 -sha256 SHA-2 256 bits -sha512 SHA-2 512 bits -verify options: -ignoreMissing Ignore missing files (default: off) -showNew Show new files (default: off) -ignoreChecksum Don't calculate checksum (default: off) -update options: -removeMissing Remove missing files (default: off) -ignoreNew Don't add new files (default: off) -pretend Show what would happen - don't write out XML (default: off)
My original Minifig Collector app (which was the first Android app I ever created), which has seen over 150,000 installs, just got a major facelift and some new features version 11.0. It now has a more modern-looking UI, can import/export your figures to Brickset, and let’s you finger-swipe back and forth. Check it out!
Version 2.0 introduces tablet support along with a complete visual facelift. In addition, there are several performance improvements that make the app much faster when browsing, and I’ve added the ability to browse minifigures, sets and heads by name (in addition to by year and theme).
Check it out!
Note: LEGO® is a trademark of the LEGO Group of companies which does not sponsor, authorize or endorse this app.