I would think the security concerns would be front and foremost. When I hit up google for a list of sites, I want a list of sites. Whether my browser visits t

I would think the security concerns would be front and foremost. When I hit up google for a list of sites, I want a list of sites. Whether my browser visits them or not is up to me - I don't want it happening automatically. Now, personally, I can turn this off, I know, and I also understand the speed advantage for end user retention. People might say 300ms doesn't matter to them - maybe not consciously - but it certainly DOES matter when it comes to retention. People like faster sites automatically - it's a subconscious thing - very well proven by good studies. (amazon, etc) a 300ms savings on page load is a HUGE win from the site owner point of view. Give the site owners some kind of passive control over this feature (a-la robots.txt for spiders) so those who are really concerned about bandwidth can opt out (though if you are top ranking for a google search term you probably WANT that traffic - that's money down the drain otherwise) and appropriate controls, and it's a good idea. In fact, it's an inevitable idea. with it's ups and downs. It's going to happen - so let's roll with it.