When your company is launching a new product then what strategies you will apply for developing sales of existing product in the market ?

They are quite a number of strategies but let me share the ones im more familiar with,

Promotion of existing product,Marketing should be mantained as well to avoid carnibalisation,Sponsorship campaigns promoting existing products under its brand should be maintained or improved

New tactics are required to get the notice you deserve. So here are some steps for a successful launch in these fickle times:

1. Start early. Don’t expect reporters to write about you when you want. Get a head start and begin preparing long before you plan to launch. A rolling launch is a great way to keep the conversation going. Start your outreach activities 6-8 weeks before the official launch date and then keep the news going up to, and beyond the official launch date. The steps below describe how to do this.
2. Make the product or service available to important influencers as a first step. Influencers can be friendly customers, prospects, or even bloggers who have an sizable online presence. Encourage these people to use your product or service and then write review articles or posts. These folks are also great resources to talk to analysts about your offering pre-launch.
3. Brief industry analysts during this early phase as well. Scheduling calls with these folks takes time so do this early. Invest the time to write compelling briefing requests. These guys are busy, so you will want to make sure your meeting request clearly states why it is worth their time to hear about your offering.
4. Seed the social space with “leaks.” Target people who are naturally eager to learn about your offering. For example, ‘coming soon’ tweets and ‘leaked’ photos of your product create an aura of intrigue that builds interest. Apple is a master of this technique.
5. Don’t expect a “big bang” release unless your product or service is truly revolutionary or if you are Microsoft or Apple. Unless you have a massive launch event planned, the official launch date should only signify the day your product is actually available.
6. Keep the release rolling. You don’t know when reporters will have time to write, so give them some opportunity to write about the offering after the official launch date. Continue to produce fresh news like announcements concerning novel uses of the product, customer stories, details about how the offering provides return on investment (ROI) to customers, etc.
7. Do something unusual during the release cycle. Some examples include creating a funny video, doing a stunt centered around an industry event, publishing a survey that supports the value of your product, or creating an interesting infographic that describes the need for your product. As an example, for a recent product launch, I created a mock public service announcement (PSA) website that warned of the ‘dangers’ of using our new mobile product while walking. The irony created an enormous buzz around the launch and even led to a huge spike in free product downloads. You can check it out here.
8. Get partners involved. Channel and marketing partners who have a financial stake in the success of the launch are natural allies. The more people that are talking about the release, the better chances it will get pickup.
9. Make it easy for people to learn more about your product with free trials, downloads, product videos, and demos.
10. Ignore the elements of the launch that do not drive business. Unless your offering appeals to a mass consumer audience, don’t focus on the number of Facebook likes and Twitter followers you collect. Rather, use these social channels for more meaningful engagement. See who is talking about your offering online and then make contact with them. See how these folks can help you further promote your offering within their social circles.

people like changes just aware the people about product and his advantages and your price must be economical because must of people think about saving.      

1. I will identify the 20% of the customers giving the 80% of the business for the excisting products and focus on sustainability as increased usage

2. Come up with reminder messages to ensure as i launch the new product the excisting business is not missed

3. use "push" strategy where i block competation with volume stocks to the stockist hence they have no choice other that push the products out of their shelves

5