My one keywords that is web design company. it always fluctuate in SERP whereas i did lot's of work for it's keywords but I am not able to make stable in same position in SERP. now i am confuse that now what's do for stable.
Actually there is no permanent in the world of SE it just normal but just do the right thing to keep your site in the competition.
"Web Design Company" this keyword is too much competitive and too many competitors are working on exact this keyword, so it happens.