Summary: First impressions are weighted heavily when we form opinions of people. Once those opinions are formed it takes a lot of evidence to the contrary to cause us to re-evaluate our opinion of that person.
Edit: another example is the well-known result that better looking people are rated as smarter, nicer, more competent, etc. IIRC, they're even less likely to get sent to prison and receive lighter sentences if they do.
Starbucks broke an anchor effect by making their stores about ambiance. As a result, customers were willing to spend double the usual price on the same coffee--or of slightly higher quality--because the anchor was broken from Dunkin' Donuts' coffee. It was a different experience and therefore, a different price scale was acceptable to customers.
The best example of this bias is when people are asked to estimate the value of
1 x 2 x 3 x 4 x 5 x 6 x 7 x 8 x 9,
the number they come up with is around ten times lower than when asked to estimate
9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1