How to progress in the zoo of the mobile game township

When you reach a level you can buy for gems new animals. Fortunately, If you have not enough or no gems you can buy animals with enough townhip bills
To reach the next level you have to get enough popularity points which you earn only with the café/movie theater or similar.
So whenever you have the chance to buy one: buy it right away. The more you have the faster you can get the points for products.
I use usually left over products (from my orders ) to fill the baskets in the zoo sales outlets. Sometimes when an item is hot in the zoo it is even a good deal when buying the item in the market to sell it at the zoo. Although, the money made is marginally you get additional points without losing anything.