Good stuff. Niche idea for ya: consider government contractors. Gov sites tend to be atrocious. Manual change tracking can mean you find a $1M RFP weeks earlier, which increases chance of winning. (Consider mda.mil. There's no email signup. What they consider a 'newsletter' is in fact a list of PDFs hosted on their site.)
And that's federal gov contracting. State/local is even more of a Wild West. So much so that many, maany companies just never have the bandwidth to even find RFPs and navigate those ancient sites.