Not much of a sales person.

"What does online home business do for the quiet introvert?" From Larry.
As Bruce mentions there are so many ways to successfully market on-line.
For the Introvert, one method used well is a personalized E-mail marketing program, where the letters are like private dialog.
I believe an Introvert can more easily develop LONG term relationships for more repeat business.

It seems to be this question is more about the "social" person verse one who is not social nor has no interest to be.

Effectively there are 3 types of internet marketing - social, seo, and list building. If you don't like being social, that leaves seo and list building.

However list building within and of itself vastly revolves around interacting with the people on your list - thus it to becomes social.... leaving you one option.

SEO.

So in my opinion you have but a few options - figure o

Interesting observation Larry. Being extroverts means that that they soon become bored and move on to new and more exciting things. They may be able to sell things, but will they be there for backup service if needed? That's where the persistent introvert will really come into their own.