Be careful of summing together reactions from different people as if they represented a single common or average reaction.
There are loud critics of each your examples... but very few people, other than the relentlessly negative, are likely to be sour on them all. The fact that there are enough naysayers to fill any given comment-thread or link-aggregator is just evidence of the breadth and opinion-diversity of the audience now commenting, and that our modern filtering systems especially promote dissent and controversy.
(I say this as someone who thinks Facebook has great prospects, Twitter has challenges but will probably figure something out to justify its recent valuations, Zynga may be questionable on social-value grounds but will likely remain a strong business... and yet there's something fishy about Groupon, from its top-level accounting to its street-level dealings with small-businesses and customers, that makes me think by 2013 Groupon could be considered Chicago's Enron.)
There are loud critics of each your examples... but very few people, other than the relentlessly negative, are likely to be sour on them all. The fact that there are enough naysayers to fill any given comment-thread or link-aggregator is just evidence of the breadth and opinion-diversity of the audience now commenting, and that our modern filtering systems especially promote dissent and controversy.
(I say this as someone who thinks Facebook has great prospects, Twitter has challenges but will probably figure something out to justify its recent valuations, Zynga may be questionable on social-value grounds but will likely remain a strong business... and yet there's something fishy about Groupon, from its top-level accounting to its street-level dealings with small-businesses and customers, that makes me think by 2013 Groupon could be considered Chicago's Enron.)