Can I add my own sales data to GPA? 2 2

[WOLVERINE335]

For example, if I buy or sell a CGC book at a convention, can I go home and input that data into GPA?  I don't mean, update my personal collection on their website... I mean, indicate the date, and the serial number of the comic, and the sale price, so that they update their data for all to see?

BTW... while this would be useful if everyone were honest, we know everyone is NOT.  So I'm hoping the answer is NO.

The reason I'm asking is because I wonder about some of the sales data I see there.  Some can be confirmed by direct link (Heritage and ComicConnect, for example); some can be found from eBay past sales (albeit without a direct link).  But other books listed as having been sold at such and such price, be it way higher than expected -or way lower than expected- can't be confirmed anywhere.  Which leads me to wonder if it's possible some people are gaming the most recent sales data by inputting their own sales.

I wish ComicLink would include their data.  And I wish all the data that was included had a direct link.  Because sometimes a book seems off, but then you see the particular copy and understand why it went for way less.

[Danno616]

On 3/2/2024 at 3:41 PM, WOLVERINE335 said:

For example, if I buy or sell a CGC book at a convention, can I go home and input that data into GPA?  I don't mean, update my personal collection on their website... I mean, indicate the date, and the serial number of the comic, and the sale price, so that they update their data for all to see?

 No. GPA doesn't take sales data from individual subscribers.
 

On 3/2/2024 at 3:41 PM, WOLVERINE335 said:

The reason I'm asking is because I wonder about some of the sales data I see there.  Some can be confirmed by direct link (Heritage and ComicConnect, for example); some can be found from eBay past sales (albeit without a direct link).  But other books listed as having been sold at such and such price, be it way higher than expected -or way lower than expected- can't be confirmed anywhere.  Which leads me to wonder if it's possible some people are gaming the most recent sales data by inputting their own sales.

GPA receives sales data from at least 10 seller/auction sites, most of which don't link to the sale. One not listed on their site that I know provides sales data is Collectors Comics.
 

On 3/2/2024 at 3:41 PM, WOLVERINE335 said:

I wish ComicLink would include their data.  And I wish all the data that was included had a direct link.  Because sometimes a book seems off, but then you see the particular copy and understand why it went for way less.

On one hand, Comic Link providing sales data would result in a more accurate snapshot of FMV. On the other hand, FMV of many books likely would be much lower than they are now. At least that's what I've gleaned tracking many books in CL auctions over the last few years.

I'm guessing that a majority of the sales listings that don't have links are coming from eBay. If that's accurate, with a little effort, then you should be able to track down at least the recent sales or those within the last year by searching through eBay's past auction listings. I've done so a number of times.

[WOLVERINE335]

Thank you Danno616.  Appreciate the thorough response!

Personally, I don't understand why any auction site wouldn't want to give, and especially LINK, their sales data.  It's free advertising!  Be it a high price OR a low price, you'd get people clicking the link to check out the particular book to see why it went for so much (or so little).  Either way, that's traffic going directly to their website.

As for auction houses not wanting to show lower than FMV sales... that too is actually counter-intuitive.  If people think they can get a "deal" at a particular auction house, it will drive more buyers there... which in turn will RAISE the prices... which in turn will drive more sellers to auction their books there.  Rinse and repeat.

So from a business standpoint... as far as I can tell... it makes absolutely no sense for an auction house not to participate in giving GPA their sales data.