The latest comScore search ranking report indicates that Google is maintaining its strong lead in the search market and perhaps that Bing's growth is slowing.

Bing's search market growth may be slowing, according to the most recent comScore search ranking report. The research firm found that Google sites maintained their strong lead in the search market in May, and Microsoft sites failed to demonstrate growth.

ComScore also points out that the explicit core market grew 7 percent in May, and Google accounted for 65.5 percent of explicit core searches, up slightly from 65.4 percent in April. Meanwhile, Yahoo sites and Microsoft sites, both powered by Bing, maintained their 15.9 percent and 14.1 percent shares, respectively. This means Google represented 11.2 billion of the 17 billion explicit core search queries conducted last month, where Bing fielded 3.1 billion queries.

In the total core search market, Yahoo sites grew 1.7 percent. It is, however, worth reminding marketers that while “total core search” is a larger market than “explicit core search” (19.3 billion queries to 17 billion), the former refers to searches that do not necessarily end in engagement. (Pauses are measured as “implicit engagement,” while queries leading to clicks on results are counted as explicit engagement/part of explicit core search.) Microsoft and Yahoo sites together fielded 6.3 billion total core queries, reaching half of Google's 12.2 billion – but searches without explicit clicks may be of less of interest to brands.

It seems Bing will need to up its game if it wants to gain more search ground; Brafton has reported SMX Advanced experts suggest Bing's search bot does not discover pages as easily as Google's search crawler and this may partially contribute to its static share.

Of course, Bing's Facebook Friend Effect is Microsoft's big push to gain search followers, and the new social integration wasn't released until mid-May, so its impact on the search market will likely take time to unfold. Bing's Stefan Weitz seems confident that social search is the wave of the future and that social data will propel Bing. Future search ranking reports will tell…

Katherine Griwert is Brafton's Marketing Director. She's practiced content marketing, SEO and social marketing for over five years, and her enthusiasm for new media has even deeper roots. Katherine holds a degree in American Studies from Boston College, and her writing is featured in a number of web publications.