Purely from a performance perspective, browser & ISP caches are more likely to have the .com TLD cached when compared to a .net, .org, .tv, etc. and hence needn

Purely from a performance perspective, browser & ISP caches are more likely to have the .com TLD cached when compared to a .net, .org, .tv, etc. and hence needn't look it up with the root servers. This probably results in a performance optimization of .25% to .5% when compared to the entire page being downloaded but none the less ;-)