You can make a fortune in land.  Having said that, I will not sugarcoat what is probably one of the most difficult types of real estate investing.  The reason you can double, triple (or more) your money in land is because it is one of the least understood real estate investments.  This provides incredible upside if you know what to look for and what to do because very few people know what to do.  This is no different than any business however.  Think about used cars, for instance.  If you know cars inside and out, you will be able to buy a great deal from a person selling their car and doesn't know its value.  You can then turn around and sell it at a profit.  You have capitalized on your knowledge.  You can fix the fender, buff and shine and even make more money.  The same thing applies to land only hardly anyone knows anything about land.

The key elements in making money land are the following:
1.  Know your market.  Don't even think of buying land outside of the market area you know intimately.  Little things can trip you up even if it looks like nothing can go wrong.  Start looking at every land parcel in your market.
2.  Dream team.  You can't do it alone.  You will need to have close relationships with a civil engineer, land attorney, Zoning official, site contractor, real estate agent and lender.
3.  Understand what sells.  You have to know what type of land is selling in your market and at what price.  You will need to have better quality at a lower price.  Land is the hardest asset class to sell and has no cash flow.  This is very important.
4.  Know your zoning.  Almost every town has zoning regulations which describe in a table, usually, the basic requirements to have a legal lot.  Frontage, acreage, setbacks, etc.  In areas without public water & sewer, you will also need to know health codes, soils, and wetland issues  Essential to know.
and finally,
5.  Create value.  This is what its all about.  You can buy land at a discount and flip it or you can really make money by improving it, then selling.  The types of improvements include, zone changes, approvals for a building lot, subdividing, land enhancements (access drives, viewscapes, & beautification), free cuts, merging of title and conservation tax easements, to name a few.

Once you have a land parcel targeted, there is another major step involved which is the Purchase Agreement or Option.  How you structure this can make the difference between making money and making A LOT of money.  But that is left for another article.
Don't think you are going to go out and make a fortune in land without first having a lot of knowledge.  You will get hurt.  On the other hand, study and learn and you will profit handsomely. 
Go to my website www.realty-capital.us and read my course under education if you like.  I give specific examples of land deals I have done.  Thanks!