A pizza delivery service is often a good opportunity, only because there are plenty of potential business owners who overlook this possibility. If you have some brief experience in marketing and you organize this business in a smart manner, you will most likely dominate your competition in no time. A niche that seems overcrowded is a niche that can be monetized. In other words, this niche actually makes money. On a different note, a relatively empty niche is either new or not profitable.
While a pizza delivery service may ask for a lot of paperwork before running, I believe that it does have a series of advantages too. The most important benefit is the fact that you do not really need a bar, pub, club or restaurant. You can just rent a small office somewhere in an inexpensive area, then distribute your tasty pizza all across the city.
Studying your competition is piece of cake. Find a map over the Internet and print it in a large format. Locate all the pizza delivery services on it. Perhaps you should use one of those online maps. Mark each location and try to figure out which are is not covered. This is where you should try your luck. However, it is highly recommended to identify the reason for the low competition upfront. Perhaps the area barely has a few houses, so the demand is not too high.