Reasons to make your own faucet

1. To give something back: Faucets are a great way to help introduce new people to bitcoin, or to alternative altcoin's. A majority of faucets provide information to new users as well as offering them some free coins so that they can ‘try before they buy’, experimenting with a test transaction or two before putting real money on the line. Since this whole experience is so new and a bit complicated to people, who perhaps don’t quite trust it with their hard money, this is a beneficial way to promote digital currency and bring in new users.
2. To get traffic: Faucets are high traffic websites. It is not all that difficult to get a huge number of page views per day to a site which is giving away free money. If a website has other content or services to promote to Bitcoin users, especially new users, a faucet is a great way to bring them to make them familiar with a brand name.
3. To make money: Making a healthy profit from a faucet site on its own is a lot harder than just making a popular faucet, but it is still possible. There are a lot of these sites around today, so it's a very competitive market, and earning enough from advertising to cover the cost of the coins you are giving away and hosting costs is nearly impossible. Adding additional content to a website, or creating some kind of unique or interesting twist, is the only way to generate an income for a Bitcoin faucet.