Installling on vinyl siding is doable. However, it takes special skills not usually had by satellite TV installers.
It is not my preferred mounting location, but I've done lots of them, especially for two story houses.
The key is a tool made by "Malco" called the "Sideswiper (available at Lowe's or Home Depot for about $5), that allows the user to release the bottom of the sideing panel.
I carry pieces to precut 2x8 inch 1/2 inch thick plywood for these installs.
I'd release two siding panels, find the studs and mark their location with a light pencil mark on the outside bottom lip of the siding.
Then, I'd place two pieces of the plywod into the space or void under the siding, centering them horizontally with the wall stud.
Then, I'd mount the foot as usual.
This method works on both wood sheathing and houses with foam sheathing, since the plywood stabalizes the outer screws and holds them in place.