* Can record java version, flash version, other plugin info
* Can record screen size, browser window size, color space
* Can detect and record ad block presence
Both have their uses.
Edit, since someone has downvoted this comment without offering a contrary opinion:
To me that is actually a benefit of JS based analytics programs. When I check Google Analytics in the morning I don't want to see how many search engine bots and scrapers hit my site the previous day. I want to know how many actual human beings used my site instead.
And yes, Dataland Software "sells" interactive web log analyzer, but I can't really see how's that important?
Personally I found most of their 'reasons' to be fairly contrived.
I think it would be possible to come up with a much more balanced point of view than the one given in the article when comparing tag based analysis and log based analysis.
Both have their uses, some of the reasons given hold water but most of them are pretty thin.
You could make an equally unbalanced list of 10 reasons why tag based analysis is 'better'. The important thing to notice is that tag based analysis is very convenient and can give you a bunch of information that would be fairly hard for a log file based analyzer to provide.
Log file analysis has it's place though, especially when you need to dig in to locate a problem. That's when a log file analyzer is next to useless though, you are basically going to go hunting through the raw logs in order to find your evidence.
The article smacks of a business giving me reasons to buy their product in the light of free competition. (The other alternative to paid log analyzers besides tag based analysis is of course an foss implementation of such a log analyzer).
Sorry, I'm not in a mood for a flame war...
1) you don't need to edit HTML code to include scripts
The authors assert that you'd have do this by hand if you had a lot of static html. This is incorrect (you could easily insert the code using some script), but it also doesn't make sense, most larger sites (if not all these days) are dynamically constructed and adding a bit of .js is as easy as changing a footer.
2) scripts take additional time to load
3) 'if website exists, log files exist too' (...)
This is really not always the case. Plenty of very high volume sites rely almost entirely on 3rd party analysis simply because storing and processing the logs becomes a major operation by itself.
4) 'server log files contain hits to all files, not just pages'
That's true, but for almost every practical purpose that I can think of that is a very good reason to use a tag based analysis tool rather than to go through your logs. The embedding argument the author makes is fairly easily taken care of by some cookie magic and / or a referrer check.
5) you can investigate and control bandwidth usage
Bot detection and blocking is a reason to spool your log files to a ramdisk and to analyze them in real time, to do it the next day is totally pointless. Interactive log analysis (such as the product sold by this company does) can help there, but a simple 50 line script will do the same thing just as well and can run in the background instead of requiring 'interaction'.
6) see 5
8) you can find out about hacker attacks
True, but your sysadmin probably has a whole bunch of tools looking at the regular logs already to monitor this. Basically when all the 'regular' traffic is discarded from your logs the remainder is bots and bad guys. A real attack (such as a ddos) is actually going to work much better if you are writing log files because you're going to be writing all that totally useless logging information to the disk. Also, in my book a 'hacker' is going to go after other ports than port 80.
9) log files contain error information
This is very true, and should not be taken lightly, your server should log errors and you should poll those error logs periodically to make sure they're blank (or nearly so) in case you've got a problem on your site.
10) by using (a) log file analyzer, you don't give away your business data
well, you're not exactly giving away your business data, but the point is well taken. For most sites however the benefits of having access to fairly detailed site statistics in real time for $0 vs 'giving away of business data' is clearly in favor of giving away that data.
Google and plenty of others of course have their own agenda on what they do with 'your' data, but as long as they don't get too evil with it it looks like the number of sites that analyse via tags is going to continue to expand.
We use Google Analytics. I noticed Google Bot, but not other buts, has increased crawl frequency steadily with our recent traffic spike, but the number of visitors from search engines is still quite low at this point. This correlation hints that Google may be using traffic data to prioritize crawl rates and it would seem a logical extension to prioritize search results.
You can have a tracking pixel in noscript tags as backup.
We do rotate our logs up to S3, but haven't done anything with them thus far.