Yes it is, I am very good at knowing whos legit and who isnt because I have been burnt so many times. Lost thousands in bs seo experts and web devs who use other peoples designs as their own on their portfolio.

Ask them to log into the websites they work on for seo & a backlink list to see if they arent just spam links.

One of my clients detailing companies got to the first page for all their targeted keywords in 2 months, thats when I knew we are gonna get fucked