The site is just a wrapper for a Google Custom Search Engine.
I'm just putting it on a memorable domain and (barely) styling the results.
No. The site is too simple to qualify for google adsense. I could add some BS content to reap the massive few cents of reward, but I'd rather just bask in the smug self-satisfaction of being helpful.
The GSE is pretty limited with what it can do. Basically if you can add it to a google search via arguments or URL modification, then I can probably slap a UI on it.
I'd like to add a subReddit filter, mobile filter, and time-sort, but haven't gotten around to it. Google doesn't seem to be indexing the vote/point data, so I believe that is out of the question for the time being.
Because this is considered a 'personal' site, the Google custom search engine terms of service allows me to offer it for free. Reddit would have to pay hundreds of thousands of dollars per year for it. Google also offers a 'custom search appliance', but it seems more targetted towards intranet document indexing, and is also prohibitively expensive. Even if they didn't check, presumably Conde Nast would not be ok with outside ads on their site.
Google's index doesn't seem to be recording vote data in the snippets, and crawls with slightly unpredictable lag times, so basically the google approach lacks the fine tuning knobs involving user accounts, votes, and crawl speed that a server-side database aware solution would offer.
The bottom line is that getting a fast, accurate customized search running on a massive, distributed, high-write database is a hard problem (Trust me, I know).
If anyone tells you that it's just a matter of 'dropping in' Google/Fulltext-indexes/Lucene/Solr/etc, then they have no clue what they are doing.
There's no simple solution, and Reddit's small team does heroic work under their constraints.
This has been really neat for a 1 hour total project, and the response from redditors has been awesome for such a simple thing. The reddit admins have been really understanding about everyone hammering them over search, especially people who don't understand what a hard problem it is.
If you're a reddit admin and ever in DC, let me know and I'll buy you a beer =). From what I understand reddit staff aren't allowed more than 100 miles from the left coast in case the mothership returns to roswell, but exceptions happen.