The scary answer is FOREVER. They simply don't "expire."
Most blog host sites that offer free blog space will not fry off inactive blogs. There are some rare exceptions to this rule. A good example of this is Geocities. I remember when I first started teaching Geocities was the most popular place to get a free teacher website. I started one and occasionally updated it, but eventually I switched schools and, out of site out of mind, I forgot about it. Geocities was eventually sold off, absorbed, tweaked, and ultimately 38 million individual sites were fried off when Yahoo, the company that acquired Geocities, decided to change the format. Geocities is only in existance in Japan now and my original website from 1999 is long gone. This is not unusual, but unless the actual website closes, chances are your stuff will still be chilling out there in cyberspace incomplete and lonely, just waiting for you to remember or rediscover it.
Despite my best efforts to Google myself and whatever I thought I named my bucket list, I cannot locate it yet. I am not too concerned as I have a more modern, updated version, but the idea of this internet detritus got me thinking about just how many abandoned or forgotten blogs there must be out there. The sheer number of websites and blogs out there that are lonely and not updated simply because they are forgotten is mind boggling. Estimates are that there are 12 million bloggers. Of the blogs created, 60% to 80% are abandoned within the first month. Most that are not abandoned are just updated sporadically at best, and then, with content that average reader has no interest in i.e. personal travel, family updates, etc. I found a great site that has research data about blogs and blogging at http://www.caslon.com.au/weblogprofile1.htm which made for very interesting reading. I have found my forgotten blog is not alone by any means.
Will I ever find my original bucket list? Probably not. Do I really care? No. But I kind of look upon abandoned blogs as the trash of the internet. Who is going to clean up all this scrap? Arguments are they are like the library at Alexandria and no one should. We are free to use it for historical documentations. Snapshots of our modern times. Material ripe with our culture so that future generations of users can better understand those that came before. Whatever. I guess I will just add "Find my original bucket list" to my current bucket list.
