Pretty much every decent small and mid cap, public company in America, that gives a crap about their shareholders or creating an active market for their stock, has an IR/PR firm.
For that matter even those large corporations who do not have their own in house, dedicated IR/PR personal, outsource their Investor Relations.
For example Ruder Finn in an Investor/Public relations agency who works with clients like...
Caribou Coffee
Johnson & Johnson
Kraft Foods
Microsoft
Novartis
PepsiCo
Pfizer
I guess you would be 'suspicious' of them as well??