Hey guys! Need your many awesome brains. This may be a very basic question but am hoping you can help me out with some insights beyond "because Google says it's better".
I only recently started working with SEO, and I work for a SaaS website builder company that has millions of open/active user sites, and all our user sites URLs, instead of www.mydomainname.com/gallery or myusername.simplesite.com/about, we use numbers, so www.mysite.com/453112 or myusername.simplesite.com/426521
The Sales manager has asked me to figure out if it will pay off for us in terms of traffic (other benefits?) to change it from the number system to the "proper" and right way of setting up these URLs. He's looking for rather concrete answers, as he usually sits with paid search and is therefore used to the mindset of "if we do x it will yield us y in z months".
I'm finding it quite difficult to find case studies/other concrete examples beyond the generic, vague implication that it will simply be "better" (when for example looking at SEO checklists and search engine guidelines). Will it make a difference? How so?
I have to convince our developers of the importance and priority of this adjustment, or it will just drown in the many projects they already have. So truly, any insights would be so very welcome. Thank you!