Always disclose your affiliate relationship. Most visitors will probably understand that graphic ad will lead to your getting paid, but if you write a review or use an in-text link as a recommendation, you want your readers to know that may lead to compensation as well. This ensures you retain transparency and trust with your readers, but also, it's required by the FTC's endorsement rules.
The frequency and method of payment vary as well. Most programs pay their affiliates monthly, although a few pay more frequently. Some require that affiliate earnings reach a specific threshold, which can be as low as $25 or as high as $100. Some programs don't have a threshold. There are programs that pay through direct deposit into your bank, but a vast number pay through PayPal.
There are more than half a billion active websites under the sun and most of the (almost 70%) of them struggle to get traffic due to the high competition and expense of the process like SEO or Digital Marketing. However, you can simple buy targeted traffic from various sources at any time you want! Every paid ad campaign is an attempt to get traffic in exchange of money. However the reasons behind getting traffic are pretty different from each other. Some people buy traffic to get sales, some buy traffic to get leads, some buy traffic for brand exposure, some buy traffic to gain authority and improve rank on several metrics and so more.