Joel Spolsky said "get big fast" is a good strategy if you win by taking the market and "grow slow" is better if there is a hugely crowded market with lots of entrenched competitors but either way picking a strategy early on is really important.

The talks that really hit home for me had a theme of pushing through and not giving up. Those were Jessica Livingson about the common problems she sees startups face over and over and those from the founders of Pinterest and Weebly about all the time and commitment it took to become successful.