Archives for December 2007

Subdomains and subdirectories

Towards the tail end of PubCon, I noticed a spate of articles talking about subdomains and subdirectories in Google, and I wanted to talk more about this subject in case I was unclear.

Historically, it’s been kind of a wash about when to use subdomains vs. subdirectories. Just as a reminder, in a URL such as , the subdomain is “subdomain” and the subdirectory is “subdirectory” (also sometimes called a folder). If you’re still unclear, you may want to read my tutorial on the parts of a URL.

If you throw your content into a subdirectory, usually the code is all in the same file storage space. That can make it much easier to find/edit/change code. It can also be easier to move code from one place to another. A subdomain, however, is often a domain name system (DNS) alias. Subdomains can be a little more difficult for a novice webmaster to set up, especially if words like “CNAME” don’t mean anything to you. Subdomains can be managed separately, which can be a joy (you can use DNS to decouple a subdomain if you want to migrate that part of your site) or a pain (it may be more of a hassle to juggle DNS setting instead of just using file commands to make or move directories). When I started my blog, I decided to use a subdirectory ( just to keep things simple, for example.

For several years Google has used something called “host crowding,” which means that Google will show up to two results from each hostname/subdomain of a domain name. That approach works very well to show 1-2 results from a subdomain, but we did hear complaints that for some types of searches (e.g. esoteric or long-tail searches), Google could return a search page with lots of results all from one domain. In the last few weeks we changed our algorithms to make that less likely to happen in the future.

This change doesn’t apply across the board; if a particular domain is really relevant, we may still return several results from that domain. For example, with a search query like [ibm] the user probably likes/wants to see several results from Note that this is a pretty subtle change, and it doesn’t affect a majority of our queries. In fact, this change has been live for a couple weeks or so now and no one noticed. 🙂 The only reason I talked about the subject at PubCon at all was because someone asked for my advice on subdomains vs. subdirectories.

My personal preference on subdomains vs. subdirectories is that I usually prefer the convenience of subdirectories for most of my content. A subdomain can be useful to separate out content that is completely different. Google uses subdomains for distinct products such or, for example. If you’re a newer webmaster or SEO, I’d recommend using subdirectories until you start to feel pretty confident with the architecture of your site. At that point, you’ll be better equipped to make the right decision for your own site.

Update: Made it more clear that this change has already been live for a while.

Back from PubCon

Wow, PubCon was a blast. I can’t even begin to go into a full recap, so I’ll mention a few of my favorite things:

– talking to a ton of people. I saw lots of familiar faces, but I was (happily) surprised at how many people came up just to introduce themselves and chat for a bit. Some people wanted to report spam or discuss why a site might have been penalized and some people just wanted to say hello. 🙂 I also did 3-4 video interviews that should eventually show up somewhere on the web.

– playing Werewolf Search Spam. Rand and Co did a great job on the party and printing up a custom deck of cards. I answered questions at the “Meet the Google Engineers” event beforehand, so I only had time to play a couple games. In the last game of the evening, I got to be a blackhat/werewolf. I realized that the person to my left was the healer (“Danny Sullivan” in this game), and decided to pretend to be the healer myself. Then I realized that the person to my right was the seer (“Matt Cutts” in this game. I know — my head hurt too.). As the “whitehat healer” I convinced the other villagers to lynch the seer. I got voted out early in the game, but enough people believed I was the healer (hi Jonah!) that the villagers voted out the real healer soon afterwards. With no healer or seer left alive, the two remaining blackhats played like pros and won. Just so you know, if there’s video of me celebrating with a little dance and chanting “Blackhats rule! Blackhats Rule!”, that’s why. I was just celebrating our team’s victory. 🙂

Andy Beal took my new favorite picture of me during my keynote Q&A:

Matt Cutts: PubCon Vegas 2007 keynote

(Image used under a Creative Commons License.)

– Speaking of the keynote, at one point I talked about how Search Engine Roundtable did a nice write-up of how to report AdSense spam. I thought that Barry Schwartz did the post, but in fact Tamar Weinberg had done the post. Thanks to Tamar Weinberg being in the front row, I was quickly able to correct myself.

– I got a kick out of how many Googlers participated this year. Just a few years ago, I was one of the only people representing Google at PubCon. At one conference (2005?), I did five presentations and totally lost my voice. This time around, the numbers were reversed. Four people from our webspam team (plus several other Google colleagues) spoke on panels, and that’s not even counting Aaron D’Souza, who spoke at SES Chicago. This year I’ve been trying to step out of the spotlight a little bit to make room for more Googlers to communicate. It’s really wonderful to see just how many Googlers are talking with webmasters and SEOs these days.

– In the Las Vegas airport on the way out of town, four other people were riding the tram to terminal D. Three of them were SEOs, and we had a nice chat. 🙂

PubCon intermission: cat post!

Tomorrow I’m off to PubCon, so I won’t be posting on this blog for a few days. As long as I won’t be on the blog, I might as well leave up a cat post for people to check out.

This weekend we put our (artificial) Christmas tree up. Ozzie decided to investigate:

Ozzie finds a Christmas tree!

He spent a little time getting familiar with the tree:

Ozzie hides in a Christmas tree!

Then in case the Christmas tree was food, he decided to try to eat the tree:

Ozzie tries to eat the Christmas tree

I honestly believe that he thinks that the Christmas tree is a cat toy that we haul out once a year just for him. 🙂

Okay, maybe you’re wondering how Emmy is doing? She’s a cat that likes to sleep, and especially likes to sleep on me while I blog and answer email.

But sometimes she decides she wants to relax with me in the chair. She wriggles in behind me and sleeps:

Emmy likes to sit behind me in the chair

Eventually I get tired of sitting on the edge of the chair and go do something else for a while. 🙂

I’ll be back from PubCon in a few days.

My PubCon 2007 schedule

Next week, I’ll be at PubCon in Vegas. Here’s how to find me.

– I get into town Tuesday afternoon. I’ll be on a 7 p.m. panel Tuesday night with other search engine reps from Yahoo!, Live, and Ask. Guy Kawasaki will be moderating.
– On Wednesday, I’ll be sitting in on sessions during the day. Google is hosting a Meet the Google Engineers reception from 7 p.m. to 9 p.m. After that, I’m planning to head over to the Werewolf tournament to watch how well SEOs play that game. 🙂
– On Thursday morning, I’ll be doing a keynote question and answer session with Brett Tabke.
– On Friday, I’ll be hanging out for hours at the PubCon. My plane flies back Friday evening.

If you’re at PubCon, please walk up and introduce yourself — I’d love to meet you. 🙂

Recap of last week

It’s been a busy week. Some of the stuff I didn’t get a chance to talk about this week:

– It sounds like Google will participate in the 700 Mhz wireless auction. It also sounds like there are anti-collusion rules that mean that participating companies aren’t supposed discuss the auction, so I don’t expect to talk about this subject anytime soon, even on my personal blog. 🙂

– Google Reader added both recommendations and drag-and-drop. To me, these releases show how the Reader team is in tune with Reader users. When I did an informal poll of desired Google Reader features, those were the #1 and #2 most-requested features. I’m sure that the Reader team was working on these features before that poll. The recommendations feature is especially nice though. Among my recommendations are AI3, Cre8pc, and BitWorking. I used to think that I really needed drag-and-drop, but I’ve gotten used to reading my feeds without rearranging their order.

– Blogger is experimenting with allowing OpenID. I believe this is a good thing for identity across the web, but I’ll be the first to admit that OpenID hurts my head a little bit. 🙂

– Google announced that it wants to fund research to make renewable energy cheaper than coal. The initiative is called RE<C (Renewable Energy Cheaper than Coal). In my experience, Larry and Sergey have been interested in energy issues for a long time. Remember the solar panels? The push for more efficient power supplies? When Larry pleaded for standardized power adapters in his Consumer Electronics Show (CES) keynote? To be fair, it is pretty cool that phone manufacturers have decided to standardize on the micro-USB standard for charging. The announcement also caught my eye because I enjoyed reading about high-altitude wind-power production by Makani Power in Cringely’s column a few weeks ago.

Techdirt covered a back and forth and back regarding Google’s partnership with the University of Michigan for book scanning. If I had more time, this is something I’d like to dive into more. U of M has posted their agreement with Google if you want to dive into it more.

– Google Maps added a terrain view. That may not mean much to people living in flat areas, but if you’re from Eastern Kentucky, it’s fun to see where all the “hollers” are:

View Larger Map

Google Maps for Mobile added the ability to locate your phone even if you don’t have GPS based on your cell tower. Also pretty sweet.

– This is older, but Google Checkout added a “Oops! Undo that purchase” option. For up to 15 minutes after a purchase, you can undo that purchase. Speaking of payment stuff, I like that PayPal started offering a service to generate a one-time MasterCard number. I’m not whether Checkout offers this, but it would be nice. And still on the subject of credit cards, I thought this was an interesting post.

– I thought Pandia’s parody of Black Hat SEO was hilarious. I need to circle back around to Pandia’s Christmas wish list and see how we did.

– If you have an iPhone and use Gmail, I really really recommend reading this overview post about how to make IMAP on an iPhone work well with Gmail.

Update: Crap, I completely forgot the voting experiment for personalization. Congrats to the folks that are playing with that. 🙂