Answer by TheTechDude · Nov 13, 2012 at 10:51 PM
Yes and no. Technically the website should get slower because the server on the other end has to find that file and the more files you have on your website technically the site should be slower. However, it really should not be a noticeable difference.
One place that you would really notice the difference is on this site if you have as much Karma as like I do this site is extremely slow. If I run the browser in private mode so I am logged out this site is much faster. However, this is a bug in OSQA that was fixed for a while and has come back again.
Answer by Razor512 · Nov 14, 2012 at 12:28 AM
anything that causes more data to be downloaded by the client will slow things down.
Another area with slowdown is lag spikes during automated backups. While there will always be lag due to reduced IO's for the clients, more data means a longer backup.
another issue is if you are running a forum,, if you have hundreds of thousands or millions of posts, then if you replace the forum software then the database can take a few hours to a day to index
PS if you have a web hoster with limited bandwidth, then it is beneficial to optimize all content that is automatically loaded when the user heads to the page. (You would not believe how many people will slap a 1600x image on their website, then use html to resize it (meaning the user is downloading the full size image and then their browser does the work of resizing the image.
(with a major example being sites like instantz many of which exhaust their bandwidth quickly each month (wonder if has anything to do with the 3MB images that are resized using HTML on the main page)