is the largest search engine optimization firm, according to the new edition of The MarketingSherpa Buyers Guide.

The guide surveyed 120 firms and noted that WebSourced, which operates, has 54 full-time employees and more than 1,050 clients.

“We have seen fantastic growth in this industry over the past couple of years, and it shows no signs of letting up,” said Andy Beal, vice president of search marketing for