How to Manage Product that in Mature Stage ? (VitaCharm & Yakult)

There was an interesting question in a yahoo group that i already joined in (marketing-clubs) about how to increase sales turnover of healthy probiotic drinks (the brands are VitaCharm and Yakult) that he/she thought already in mature stage. Before giving solutions let me asking questions about those products to make sure that those products are really in the mature stage:
1. Are the costs decrease due to experiencing many times of production and production volume is increasing ?
2. Does the volume of sales stable in the peak position and difficult to reach higher ones?
3. Are there many competitors in the markets?
4. Do the profits go down ?
If questions 1 to 4 are answered with Yes then there is a high possibility that those products are in the mature stage.

How to increase sales turnover and profits of products that in the mature stage? in this case that products are healthy probiotic drinks Yakult and VitaCharm. These are some suggestions that i think will rejuvenate that products to be in the growth stage again:
1. Product Innovation!:
a. produce Yakult or VitaCharm with delicious flavors: strawberry, chocolate, orange, or others.
b. launch Yakult or VitaCharm in various packages: can, bottle, or other interesting form of packages
c. produce Yakult or VitaCharm in various substances, e.g. jelly
2. Marketing Innovation!:
a. launch new brands for those innovated products
b. join with healthy food producers to launch marketing programs to educate younger customers such as children (for example giving free healthy breakfast plus Yakult or VitaCharm with flavors for junior high school students) because in many cases many products that bought by mommy are chosen or wanted by her children and those children will grow up and become next generation of Yakult or VitaCharm's customers
c. repositioning from healthy probiotic drinks to hip modern drink for everyone
d. co-branding with other products, but this must be done cautiously, because co-branding can also hurt Yakult or VitaCharm's previous brand image.
3. Distribution Innovation!:
a. launch center for healthy intestine with cooler name (such as "Rumah Sehat Yakult or VitaCharm") nearby malls where customers can check their health up and can have clear information how to take care their intestine's health by some ways, one of that ways are consuming Yakult or VitaCharm everyday
b. distribute new innovated hip products to hip places such as restaurants, cafe, etc.