Today Seth posted a new blog on the Foundry Group site titled Foundry Group’s AdTech Investing: Adhesive. While we’ve seen a billion AdTech related investments, we’ve only made a few of them over the past three years. We are huge believers in the macro of digital advertising, but we think the morass of much of the online ad world is just that – a morass. So we’ve avoided large swaths of the digital advertising world, instead focusing our energy on the ones that fit in our Glue theme.

We realized a while ago that we really had two types of companies in our Glue theme. The first set are companies that provide a key layer of software on the Internet, much of it at the application or machine to machine level, such as Gnip and Standing Cloud. The other set are companies that provide glue between systems in the AdTech universe, such as AdMeld and Triggit.

We’ve resisted talking about being AdTech investors since there is so much of AdTech that we avoid. However, when we realized that we were investing in a lot of “Glue for AdTech”, it seemed logical to categorize these investments in a new theme – Adhesive.

The companies we’ve invested in that we categorize as in the Adhesive theme are AdMeld, Lijit, Trada, Medialets, Mandelbrot Project, Triggit and Integrate. For more on how we are thinking about this, take a look at Seth’s post titled Don’t call it AdTech. It’s “Adhesive”. And if you want to see how we’ve categorized all of our investments by theme, take a look at the new portfolio page on the Foundry Group website.

We’ve put up a post on the Foundry Group site about a new theme of ours we are calling Distribution. We’ve been investing in this theme for a while but have continued to formulate exactly how we think about it.

I’ve talked about our thematic approach to investing many times in the past.  Every now and then it feels like it’s worth a quick post on our current themes. They are:

Human Computer Interaction: The way humans interact with computers 20 years from now will make the way we interact with them today look silly. Sample companies include Oblong, Organic Motion, and Fitbit.

Glue: Computers love to talk to one another. The amount of “computer to computer interaction” is increasing at a dramatic rate. There’s a software layer that “glues” this together. Sample companies including Gnip and Standing Cloud.

Digital Life: We believe that people own their digital assets and should be able to access them anytime from anywhere. Sample companies include Cloud Engines and Memeo.

Protocol: Many protocols – both formal and informal ones – support extensive software ecosystems. We’ve been investing in protocols like SMTP, RSS, XML, and SMS for years and expect to continue doing this. Sample companies include SendGrid and Urban Airship.

Distribution: Giant existing online markets can be completely disrupted by new distribution methods like Facebook, Twitter, Mobile, and User-Generated Content. Sample companies include Zynga, Topspin, StockTwits, and Cheezburger.

We’ve got one additional theme that we’ll be talking about shortly. We’ve decided to split our Glue theme into two different themes as we’ve realized a particular pattern in our investment dynamics around this theme. Look for another post on this shortly.

I’ve been hinting about a new conference that we’ve been working on with Eric Norlin that complements Defrag and Glue.  Eric is about to launch it and the splash page for the Blur Conference is up.

If you are familiar with Defrag and Glue, you know they are built around two of Foundry Group’s themes (Protocol and Glue respectively).  Blur is being built around our Human Computer Interaction theme, but with a twist.  Instead of simply being able to “see cool stuff up close”, our goal with Blur will be to create an environment where you can actually use and work with this stuff.  We’ll have user-oriented demos, hackathons, and tons of crazy shit no one has ever seen before.

Plus, we’ll give away a lot of cool toys, have a ton of smart people who are working on the next generation of HCI in one place, and have some fun surprises.  And we are doing it in an environment that is especially tuned for a conference like Blur.

I’m incredibly excited about what Eric has put together for this year’s Glue Conference (as I wrote about the other day).  He’s setting a high bar for Blur, where the goal will now be to have a few brains explode!  Get ready – it’s never dull around here.