GigaOM: There has been an interesting debate going on over the past week or so that gets to the heart of one of the deep-seated conflicts within the web-startup community: namely, whether apps and services are better when they are free or when users pay for them. Dalton Caldwell, the founder of Imeem, kicked things off by saying he is going to try to create a for-pay version of Twitter, and others cheered him on by saying that an advertising-based approach makes a lot of services less appealing than they could be. Venture capitalist Fred Wilson of Union Square Ventures, however, argued that free and ad-supported is actually the best model for consumer services that want to achieve a broad reach. So who is right? That depends.