Blue Oasis, Online Marketing Greenery

Mr Tan opens a store and hopes to do some business. He sells stationaries.
Customer A drop by and wanted to reload phone credit, but Mr Tan has nothing that customer A wanted, so customer A left.
After a while, Mr Tan thinks that selling stationaries alone is not enough, he starts to sell hand phone, credit reload and other mobile thingy as well.
Customer B drop by and wanted to buy some drinks, but Mr Tan has nothing that customer B wanted, so customer B left as well.
After a while, Mr Tan thinks that it’s a good idea to sell some snacks, candies, and drinks too.
When days passed by, the business isn’t getting any better and Mr Tan had to end his business.

In real world, we visited IKEA is because we hope to buy some interior stuffs with good design;
we stayed at Hilton hotel because we wanted prestigious accomodation;
we travelled to Bali because of their exotic culture.
Customers know them well for what they’re offering it’s because that’s what they do best.

So, what do you sell? is that what you do best?