Know-How Exchange : Research/Metrics

market share is simply the sales of the brand divided by the sales of all brands in the same category. Practically though, there are two decisions to make:
1) how to define the category? Coke's market share looks a lot more impressive if you define carbonated drinks as the category, versus all beverages
2) unit sales or dollar sales (revenues)

Koen

Depending upon the category, you may be able to get some total consumption numbers from an appropriate trade association. You may be able to make some estimates about the competition and derive your market share that way.

You can also do some Consumer Research, understand the market size and brand share in the past (period)

Also you can select a representative sample of stores in terms of size and geographical coverage and extrapolate their sales of your category

竞争信息,你可以检查overs or another online resource, industry trade associations, or make some contacts with your buyers to see if you can get an idea of the competition's size or relative market share. If those avenues don't pan out, you could leverage a competitive intelligence firm to dig into their business.

If you know the accounts they sell into, you can also estimate their dollar volume based upon the account's share of sales overall and their 'share of shelf' (or at the category level, if available).

It would help to understand the category and channels you're dealing with so we can be more specific though.
-Steve