Alex,
Important question. The conversion % we reference points to a customer taking an action. It is based on a combination of metrics, such as form submissions, click to call triggers (if dealers have that implemented), or visits to a map & directions page. If the dealer wants to exclude map page visits in the percentage they can.
But, to answer your lurker's question, these are actions that a customer has taken - form submit, call, looked for directions, vs. just visited any other page. Therefore, in all the conversion %'s shown above, you are looking at people who made it to a form submit page and/or maps and directions page. - pointing to the fact that they have given an indication of shopping intent.
The metrics you see on the right hand side, % Dealership, % Inventory % Service are portraying the "within the site" conversions you describe from GA. We aggregate the pages of the website platform and map the engagement with those pages "beyond the land" on a dealership's website.
Sidebar: At a dealer's request we have taken the conversion % a step further and implemented code that allows a dealer to take into consideration form submissions that occur outside of a their own web platform, such as lightbox windows or popups. Automark, for instance comes to mind as an integration we did to show a dealer his successes in context beyond his own website forms. Once those dealer specific integrations are in place, the conversion metric alters to include that form submit as a part of that dealer's story. Which, of course, makes the original point. Every dealer has his/her own context for success - we just feel there are better, more actionable, metrics to look at than the path to the VDP alone. So, the dealer can customize their definition of "conversion" to their own liking, but we encourage them to keep the metrics purely focused on an action that indicates an outreach from a customer.
I like to apply a reach and frequency approach - Unique Users is the Reach and % Inventory Engagement the Frequency. Overindexing campaigns in % inventory point to engaged shoppers, whether they are submitting a form or not. So, I wouldn't throw that baby out with the bath water, just because they haven't yet given me their email or phone number.
I hope that helps and I'm happy to set up a time with our team to dig deeper, as I'm sensitive to this post becoming too focused on our software. Keep in mind, our blog helps dealers gain much of this insight through GA themselves, but it can be overwhelming. Our platform, within which these metrics play a small role compared to the grand scheme of insight, just takes GA a bit further and helps them from getting too far down in the weeds of the GA UI. The fun begins when you can get beyond GA and put things into action.
