There are large online dating sites that help people find each other. However, the problem of large generic dating sites is that they are too big. Sometimes it's really hard to find something or someone there.
A good example here is when you are thirsty and you want to buy a bottle of water. You don't necessarily need to go to Walmart. It's huge, you don't know where exactly your water is, and you will need to spend plenty of time to go through the supermarket. But you badly want to drink!
When you want just a bottle of water you'd rather go to a water stall. You can quench your thirst right away there. You don't have to struggle in Walmart.
The same is with online dating. There are very specific groups of people that need a special attention and their own type of services.
For example:
Gay Dating
LGBTQ Dating sites build their platform to help people of the same sex find each other. Every tool and feature is designed to work particularly for this purpose. Unfortunately, quite a few sites now can provide suitable services. Moreover, these sites have to be extra secured. First of all, not all countries are tolerant enough. And second of all, far not all people are ready to tell the world about their orientation. Here is the list of top online dating sites focused on LGBT community.