[attack]

No. Vastly more input data does generally allow for better output by these algorithms. BUT this in no way means that todays recommendation algorithms are good AT ALL.

In fact, they completely suck. And in reply to GP, netflix's recommendations suck very much too, to be frank.

Why don't companies care? Simply because it's hard to figure out how to make a lot of money even with very good recommendations.

[wheels]

For the record, more than 20% of Amazon's sales are a result of recommendations -- so just in the one case of Amazon, their recommendation system accounts for $3.4 billion in sales a year ... which incidentally is 22 times Facebook's revenue last year. Recommendations do suck, and VCs are throwing money at the problem because there's a market there that actually makes money.