[herdrick]

Yep, there are a number of surprises. For one thing, this is cumulative, so deals made and competitor relationships from 2005 are as good as from 2012. For another, having a well-flushed out Crunchbase profile makes all the difference.

Try clicking on MySpace's blue dot and see what is connected to it.

[pg]

You might want to experiment with weighting data by recency.

[herdrick]

Unfortunately most of it isn't dated. But yes it'd probably help.

[drx]

You could try scraping archive.org for some estimation of dates.