compare and contrast paragraph

my assignment is to write a campare or contrast paragraph for traditional shopping Vs. online shopping.

Well there are no similarities...actually its only a paragraph therefore i am going only for differences.plz tell me how many primary should i use can u suggest me an other primaries other than these listed below...by the way i am using alternative pattern!!!

+ can i use a primary like online shops are oopen 24Hrs as compared to traditional shops! and how can i say this? does this fall under the given primaries>?

Primaries

1. Choices

2. Conveniences

3. Pay online( i am not sure abt this one, how to say it)