What is key responsibility of Product Manager?

Responsibilities or it's role differ's from Company to Company & also varies from Industry to Industry.

(Wide topic will try to narrow at important ones :-) )

Having said that, certain Expectation is always associated universally:-

Product Optimization: Ensuring the cycle of 'Product toward's Brand' is been implied & implemented. Proper strategy has been carried to develop each category - SKU at a "Retail - Customer - End Consumer "point of view & ensure distributed or sold effectively to the 'Target Market' 

Creating Brand Awareness & Attractiveness: Develop strategies to communicate the 'Brand' to it's Target Audience (Potential Consumer), Ensuring distribution & Implementation  across all channels & retail partners, Advertising based on the category targeted, Investments in ATL & BTL thus to generate 'Pulse' & greater recognition, Image building along with ensuring ROI (Return On Investment)

Planning & Implementation of 'Planogram': This is especially used in FMCG related Industry. Ensuring Shelf attractiveness, proper display, shelfing with best combination using different methods such as fast movers, it's size & packing, display of right product at right place thus to ensure profitability per category - per outlet.

Training & Development: Providing adequate training for Promoters, sales team about the important Indicators of the brand such as : Unique features, it's quality, differential factors & other Information's. As they are the face of the brand proper knowledge & information will create significant contribution to overall development of sales, personnel & brand. 

Budgeting: One of the important responsibility of an PM is ensuring greater growth & higher profitability. To achieve that proper planning should be carried to create methodology for the future such as:

• Planning listing of new categories or sub categories (Brand) & it's feasibility
• Increasing ND (Numerical Distribution)
• Planning Growth: Based on it's historical performance growth should be set & break-down should be done 'Channel wise/Category wise/Area wise/ Sales team wise/Salesmen wise'
• Planning Investment: Investments could be ATL or BTL. Based on competition total spends should be calculated in advance thus to avoid 'under estimation of costs'. ATL includes sponsorship, creation or participation of events, trade fairs or trade shows etc & BTL is In-store Investments on either visibility (Additional shelf or space/using Innovative method's, eye-level investments etc or POS such as stands, Promo topper's, shelf dizzer's etc

Promotion's: Should prepare attractive promotion's which are going to create an pulse in the market, provide incremental business & an edge with competition. Proper Market research, gathering market Intelligence is required to carry out this & ensure greater success with best profitability & outcome.

I believe these are some of the most important ones. There are equally other important roles too which involves: Ensuring proper distribution, Analyzing Market GAP, regularly ROI on BTL Investments etc

The key responsibility of a product manager is to discover product that is valuable, usable and feasible.