Introduction

LESSON 1 - inconvenient convenience store

LESSON 2 - If you don't sell to make a profit.

LESSON 3 - Sales is vanity, profit is sanity

LESSON 4

LESSON 5

LESSON 6

LESSON 7

LESSON 8

LESSON 9

LESSON 10

LESSON 11

LESSON 12

LESSON 13

LESSON 14

LESSON 15

LESSON 16

LESSON 17