An "instalanche" is a portmanteau of Instapundit and avalanche. It is a euphemism for an increase in traffic due to a popular site, such as Instapundit, linking to your website.
Thank you for your eyes on Sunday night and your comments. I hope you do stick around because you're always welcome.
The thrill of this only matches being noticed by Rich Miller, Illinois' top state political blogger back in 2006! Although I can only guess that receiving an Instalanche resulted in more page views than I got in 2006.
On that here are a couple of links of note on instalanches. Perhaps you're reading this blog and you want to see what happens when it happens to you. ;)