The speed of Internet to Go from Walmart varies based on its coverage of specific regions. Coverage is not provided everywhere across the United States and speed is mainly impacted by the distance from a large coverage area and the amount of reception the device is receiving.
Plans that offer 3GB of data are available for the base price of $45, as of 2015, but a device is need for connection at an additional fee. Coverage at this time is very limited across the country. Researching a coverage map will help predict speeds based on availability in certain areas. Anything outside the covered areas is not guaranteed to work and will definitely achieve lower speeds, often leading to no practical access. Using a device while in a covered area will yield better results for both streaming and downloading.
The number of Wi-Fi devices connected simultaneously will impact the overall speed available, even when in a strong coverage area. It is even best practice to disconnect devices that are not in use to lower the amount of bandwidth being used, because even when the device is not being used actively, background applications are connected and using data to continually provide updated information.