As Mick pointed out in his comment, in this statement the author is considering the marketplace as a game, and the companies competing against each other as players in the game. If you then consider the total money spent by customers as "100% of the market", then Philip Morris, who was receiving 9% of that money, was in sixth place; that is, there were 5 other companies who sold more than they did. In particular, R.J. Reynolds Tobacco Company was in first place, and was probably several times larger than Philip Morris at the time.
To pull some random numbers out of my hat, the company standings may have looked something like this:
- 41%: R.J. Reynolds Tobacco Company
- 15%: Competitor company number 2
- 12%: Competitor company number 3
- 10%: Competitor company number 4
- 10%: Competitor Company number 5
- 9%: Philip Morris
- 3%: A bunch of other very minor competitors combined
With 5 companies ahead of it, Philip Morris is the 6th-place player in the market, and is clearly very far behind the leader, who is selling more than four times as much as they are. So, setting a target of increasing their sales by a factor of 5 (or, alternatively, of stealing half of R.J. Reynolds' business) is a very ambitious, aggressive target; one might say it is "laughable" because of how unlikely it is that they could achieve such a thing.