Mobile and responsive websites should allow their visitors to know whether they will find what they need within one megabyte.
I recently bought a smartphone. I can use 200 MB with UMTS before they cut my bandwidth to “snail”. This might happen quiet fast and I’m left with a handful kbit/s for two weeks.
Landing–pages are often designed with big images to gain the user’s attention. That’s fine, as long as filesize does not matter. In mobile browsing it does, though.
Let’s keep it simple: let’s show the user right away if we can help him. Ideally without big stock photos.