Use Google. Google Adwords is the most popular method for traffic. Since they are the top search engine right now it make sense to advertise there if you can afford it. You bid on keywords to get your site at the top of the search when your keyword comes up. There is more involved but it's all laid out at Google. There are a lot of other sites that use this advertising strategy called pay per click or PPC.
I mean have you seen a recent downfall of EA Community Team and their post on Reddit who got 674k downvotes? It was a heavy blow to their whole company even their stocks and shareholders suffered consequences (of course not everything was related to that post but it still had an enormous impact on their sales and pre orders). My point is, ALWAYS try to find someone with whom you can consult about those things DON’T just do them on your own, it might bite you in the back.
Not all web traffic is welcomed. Some companies offer advertising schemes that, in return for increased web traffic (visitors), pay for screen space on the site. There is also "fake traffic", which is bot traffic generated by a third party. This type of traffic can damage a website's reputation, its visibility on Google, and overall domain authority.