Volume! What to do about domains?

[sunshine]

Q:I heard of people who make like 1000USD a month with Adsense, or other ncie health figures.
He says his secret is volume. Tons and tons of pages on a variety of topics.

Even augmenting by translating the pages to variety of languages. Interesting.

My question is, if my url is say www.money.com is it enough to make my "multiple sites" money.com/travel money.com/car money.com/flower

Or should I go for www.travel.com www.music.com www.car.com to cover these new "topics" and give them a entirely different look and feel?

I guess the point here is search engine results? How likely people are to find my new sites depending on what URL I use?

Not sure, any advice appreciated!

The content of the site is going to be legit, but yes my main motivation for making these new sites is for adsense revenue.

A:
There's no need to have a domain for each topic. That's a waste of money and affort.

You could try subdomains also.
you could do equally well having separate, linked, individual domain names - so long as you don't have too many.

You could also go for sub-domains of your main URL.

All the suggested options have their pros and cons. What I would suggest though, if you decide to go for sub-directories or sub-domains, is to buy the other actual domains if they're available.

So if you want to have sub-directory food.example.com, buy "food.com" if it's available. You can always redirect it to point at your sub-directory. You don't have to use the actual domain if you don't want to, but don't give the competition a leg-up by leaving the actual domain available

Personally, I have separate, but linked domains. By spreading the load a little, this has helped during the recent indexing problems with Google, with two sites recovering quickly and two still in the doldrums.

I have had great success to date with multiple domains. While all are related, each web site is a different topic.
Host them on different servers instead of the same hosting company and cross link them... wait a week or a month... the traffic will come.