From Evernote:

Designing for experiments & A/B @etsy Dan McKinley #warmgun

Do one very minimal change at a time. 

Measure, understand and move on.

Plan to be wrong.

Prefer incremental design changes instead whole redesigns.

Why we experiment and measure?

For surprises like:

- dont open new tabs - people not used to it

- Infinity scroll good or bad? - not good for etsy

- Auto suggest in search increased sales by 4%