Here's a half-baked idea for Recommendations.
It is true that any one vendor may fit into many categories or excel in certain narrow ways but be average in many other ways. So they can't be cleanly sorted into groups like "vegetable seed vendor" or "mostly sells plugs of ornamental perennials".
And yet, it would be nice to have somewhere to look when you have a specific need, and find vendors who do excel at that one thing.
Something like multiple lists of very specific thumbs.
I can think of two ways for members to input this kind of info. One way would be for each vendor listing to have a button for "enter specific thumbs". That would then open to a page listing a big multi-level outline of all the kinds of recommendations that we can all think of.
Each member could cast more than one vote at more than one level. They might praise a company for its vegetable seeds, or only for its tomato seeds, or only its heirloom tomato seeds, or only its heirlooms for containers.
Or peppers, hot peppers, stuffing peppers, or sweet Italian frying peppers.
It seems very desirable to me to have two methods of entering recommendations. Some people will know one company that is great at something, and want to give that company that very specific recommendation even if they have to create a new leaf with only one member. But then someone else will see the category, and know of places that belong in it.
The top level outline would be very general, like Seeds, Plants, Tools, Mulch, potting mix, irrigation equipment, organic fertilizers,
The next level down would be fairly general, maybe vegetable seeds, ornamental seeds, vegetable plants, ornamental plants, cover crop seeds, bulbs and rhizomes, "Tools" might differentiate into seed-starting, shears, gloves, orchard, livestock, etc.
The next level would be even more specific, like specific kinds of plants (alpines, succulents, shrubbery ...) or specific vegetables (tomatoes, peppers, lettuce, corn ...)
Someone could give a website a thumb for vegetable seeds in general, and tomato plants in particular. If it went that deep, they could give a thumbs-up to grafted, greenhouse tomato plants, or Salvia plants in plug trays, or dwarf fruit trees for southern states.
Whenever a specific category did not exist, the member could either give the thumb to the next-higher level, or create a sub-division.
The other way to give thumbs would be to cruise the outline itself, and find or create a leaf in the outline for the thing that was your specialty. For example, "good selection of recently developed lettuce varieties with unusual disease resistances".
One person might think that was only a one-company leaf, say
http://www.bakkerbrothers.nl/p..., and create it mostly as a joke. But then someone else might know that Johnnies does pretty well at that and make it a two-company leaf. Next thing you know, multiple obscure companies are more easily findable.
if members could add leaves themselves, the outline would grow and differentiate in areas where there was the most interest.
There must be some ATP member who is a connoisseur of almost any given unusual garden interest, and knows exactly where to look for the things that no one else even knows to look for. If they could create the category as well as fill it, the very detailed structure might be self-assembling.
Sorry for the mix up. What I'd really like to be able to do is to say thank you without starting a thread for each one that says something like, "Thank you for sharing this! I didn't know where to find such-and-such plant, and now I do! ", and answered with, "You're welcome". I probably wouldn't have known about or used the company before and wouldn't have much more to talk about at that point, so the thread would likely end there. (Once I'd used the company and was happy with it I'd then write my own recommendation, so I'd likely forget to revisit the thread I'd started, anyway.)
Wahoo. I can't wait to see what you do Dave. 
