How do I find ppages in my niche?

My customer wants me to grow his facebook page, apparently in order to drive traffic to his website. Now, I started posting pictures and asking questions and seems to be working a little bit. But this page has just 400 likes ATM, so I decided I want to promote it on other pages. But I can't find any relevant pages. The build-in search is terrible.

Try doing a google search with this footprint:

keyword site:facebook.com

at least it's a relevant page in Google's eyes (and we know how their prescription glasses are failing them now)

Yes like the above poster mentioned use google and search with facebook next to the keyword for example if your niche is sunglasses search sunglasses facebook

Also i would recommend just advertising on irrelevant pages and weed out followers that way, because most of the pages you search for in your niche will likely be inactive.

Find competitors pages on forums (usually listed in signature line) and follow those links.