Keeping up with down payments?

[Nick Johnson]

I am curious how guys and gals that want to have a long career with real estate investing can perpetuate their capital.

Here is my question:

Let's say that you have $50,000 capital to start with.

You buy a $100,000 property and put $10,000 down.

At this rate you can only buy 4 or 5 before your initial nut is spent.

How do investors continue to come up with down payment money in order to perpetuate buying on a long term schedule?

I would like to buy and hold for long term rental income, not flip. Is this possible?

Thanks for taking the time to give me your ideas!