web pricing

i know the prices everybody suggest for 4k and hd , but i dont know what is the WEB option. because i want to start putting my own prices to price my footages .but i only see two options HD and WEB

Pond5 doesn't sell web size. Not sure why they keep the pricing option for it.

And why is Web or SD any less valuable than HD? Our Web and SD are used for commercial gain and profit on smart phones, tablets, computers and all marketing.

I don't think of SD and HD being LESS valuable, but rather, I consider 4K as being MORE valuable, which is why I still price the way I do.