i thought PSA is doing half grades now, not sure about the 9/10 range, but I have seen 8.5 and such...I know about regrades and such, which is why it would be tempting to take a 'top' company like BGS and switch it to PSA if it doubles the value of the card...
as for the other companies, I have seen places that allow you to make your own 'logo' and slabs very similar to PSA, which could cause confusion...
'grading' cards got popular in the late 90s...edge I think was the first to put PSAs into boxes, I know Fleer Authority, UD Graded, and Score got into it, or at least Score did a bulk submission of many rookies because in 2007 there was a ton of Adrian Peterson and Calvin Johnsons out there
and yes, I don't get people sending in, especially 'common' cards from recent years...in the grading 'boom' of the early 2000s I had some cards that were booking $20+ graded, but now it appears you should just buy ungraded stuff and WAIT 15-20 years...
look at what a 1997 Walter Jones SP Authentic PSA 10 goes for...a 2003 Topps Chrome Kevin Williams PSA 10 and other 'key' cards on whatever list PSA is using for their "Top 50" or "Top 100" of the modern era stuff and people doing sets in "The Registry"...HOF Topps RCs from the 70's and 80's are going nuts of late from what I have seen...James Lofton, Jerry Rice, Joe Montana are all selling quite well...I would assume the Marino and Elway RCs are also up, haven't checked...and then 'condition sensitive' sets like 85 Topps Football, 86 Topps Football, 86 Topps Baseball, 87 Donruss Baseball I would assume the common PSA 10s are a bit nuts...
and things that were once crazy, 2005 Exquisite Football, in BGS/PSA Gem grades are down, and those are next to impossible due to how they were packed...