The basis of any business is to make a profit and thus people are involved in a wide range of money making - or losing- endeavors filed somewhere on the ladder of success. Here are the top three profit makers. A quick note to the reader is that I am staying in the Net world and that all principles that apply to a standard business, except geographic limitations, have been factored in. The #1 Money Making Business Online Casino: With little capital investment (contrary to popular beliefs) casino have become the top money generator for Net world. Casino became so successful that the US government was willing to risk the ire of the WTO to control the market. Afterall 1 Canadian converted a couple hundred thousands into more than 1 billion in less than a year. Getting into the casino business has been made easier with the availability of software, reduce operational costs and a larger online market. PM me for more info. The #2 Money Making Business Online Gaming: everyone knows the story of runescape. From nothing to 5 million users! But online gaming is quite profitable today especial those website that are now including MMORP or some sort of skill gaming. World of Warcraft...and the list goes on. It is not so hard to start your own "gaming" business. Areas include MMORP, skill gaming, arcades, etc. A study of runscape may create some insight as to how this may be done. PM me for more info The #3 Money Making Business Search: I have 3 words for you - Google, Yahoo! and MSN. No need to make second guesses. The search business offers strong affiliate options for webmasters, since it is more difficult to dominate. The lack of competing software to the top three makes search a viable but only affiliate investment business. If you plan to really make money, you should consider one of these. You can also PM me for more info.
I was thinking about Casino. In spite of the fact that technologically it is very easy, there are a lot of obstacles for this. 1) Casino business has a lot of restrictions. 2) Not all hosting companies allow you to run casino. 3) Most of promotional websites do not allow you gambling ads. 4) etc....
I would think that a Search Engine style business would be hard to break into at this point. Google pretty much owns most of the crowd, while Yahoo! and Windows Live Search pick up the back. Nevermind all of the smaller search engines like ChaCha, AltaVista, and DogPile.
Every business you listed is a horrible idea for making money. Casinos take a lot of capital to start one without bankrupting yourself. Online gaming takes a huge investment in capital, since you need someone to create the game, plus you have upkeep expenses with servers. Search engines- don't even bother. The market is dominated and will be dominated for years to come. I can't say any of your suggestions are really profitable to the average webmaster.
Online Gaming is profitable, it doesn't HAVE to be a actual game, why not a community? I run one and it's becoming quite successful, it'll just take time to build like any good thing.