What do you like to see included in a manufacturer's website?

 Dealers and pricing...

description and msrp

Complete specifications.

• a grid of products. Grid meaning, I know which way is up, lower quality to better, smaller to bigger size, by function, by room, by user. Some sites do it well
• a 2 click access: access to any part of the web site from another, that’s just prudent UX
• information on top of or linked from the top of the page. Look at most speaker web sites, horrible 10 page scroll of meaningless drone shots before any useful info
• comparable list of features: many speaker web sites list ABC for one speaker and ACD for another very confusing
• photos of each side and in context (next to "something", and for extra, photos in a system
• btw I rated speaker web sites here, after spending about 400 hours collecting data from them - here speakerchoices.com - because they made my life miseable
• options and recommendations for e.g. vibration control, placement, room size, amp size, etc.
• company information: how old, where, why
• bonus feature: what sets you apart

As said above definitely photos of every side of the gear and in inside nothing is more reassuring than being to see inside a high quality piece of equipment. A ballpark MSRP is also helpful. Also making the technology clear is important, I want to know if an amp is Class A, AB or D, this is surprisingly hard to suss out on some sites. Also if it's tubed gear what tubes does it use?

Marketing speak, hype, and technobabble are not.