In contrast, Apple's ads have neatly-wrapped cutting attacks on Windows Vista in a humorous schtick that depicts the PC user as a fumbling fuddy-duddy and the Mac user as worldy, wise and hip.

FORBES: SiliConsumed

With 3-D printing in its infancy, Makerbot is wise to expand the user base rather than steal users from competitors.

FORBES: Inside Thingiverse, The Radically Open Website Powering The 3D Printing Movement

Like Facebook before it, Twitter was wise to build a dedicated user base before starting to sell its users information.

FORBES: Twitter To Sell Your Old Tweets

It may simply be that in the case of Google Glass, the restrictions will be greater on the developers and less so (money-wise at least) on the user.

FORBES: Clear Glass: Google's New 'Window To The Internet' Starts With No Ads And Free Services