I do a travertine foyer floor 30m in an apartment block in London I get called in around once in every 2 years. It takes 4 days to strip and seal it properly thats why it only gets done when absolutely necessary.
This is how hotels clubs think and the majority of hotels that have stone floors have limestone ones either nicely honed or polished (that are hard) so you can lenghthen the period between cleans to 4yrs no problem. These floors need experience as it can mean re-surfacing.
Shopping centres are done by their maintenance contractors, have you not seen the mess they make
