Advertising -How does this work?

[Eirikur]

Wife looks something up on her own device (laptop with chrome browser) under own google and microsoft accounts etc
I get targeted advertisements on my mobile device's (chrome) browser for exactly what she just searched on. This can't be coincidence as it too niche and exactly what she was looking for at exactly that website
Devices have nothing in common except using same home broadband wifi network and broadband account.
Any of you techies who have an explanation for this?

[paulb567]

Most probably IP targeting e.g. https://www.dbswebsite.com/blog/2016...y-advertising/

[northernladuk]

Must be really annoying getting adverts for muscular well hung men when you are trying to search for CUK threads.

[Eirikur]

Most probably IP targeting e.g. https://www.dbswebsite.com/blog/2016...y-advertising/

OK thought it might be something like that, but how can that be effective as home IP addresses for most broadband users can suddenly change, so that might result in others getting advertisements that were targeted for me
Or users in companies, that use the same IP address for all their outgoing internet traffic, may get the same adds for all staff, if one for example looked for shoes on amazon suddenly everybody would get those adds for those shoes

Or is it more sophisticated than that?
It is also worrying as incognito browsing may not be that effective anymore to get rid of targeted ads.

[mudskipper]

OK thought it might be something like that, but how can that be effective as home IP addresses for most broadband users can suddenly change, so that might result in others getting advertisements that were targeted for me
Or users in companies, that use the same IP address for all their outgoing internet traffic, may get the same adds for all staff, if one for example looked for shoes on amazon suddenly everybody would get those adds for those shoes

Or is it more sophisticated than that?
It is also worrying as incognito browsing may not be that effective anymore to get rid of targeted ads.

This is worth a watch

- slightly different scenario, but explains how the advertising works.

[northernladuk]

This article also explains something behind it and mentions the adverts guessing who's using the device based on multiple factors including IPs
How Ads Follow You from Phone to Desktop to Tablet - MIT Technology Review