Usually when a new online product unveils an upgrade, its audience numbers see a bump for the first month, before subsiding and evening out. Last month, Bing's first usage share numbers from analysis firm comScore showed a little bump, but not much of one -- yet Microsoft made as much out of it as it could.

The news this month -- the first to show month-by-month progress since the changeover from Windows Live -- may actually be more encouraging for Microsoft: It gained half a point of usage share among US users for the month of July over June, at the same time when Google and Yahoo combined lost about as much.

In a month which saw a 3.5% reduction in overall traffic month-to-month -- which is common during the summer -- Bing serviced 2% more searches for US households and universities (not businesses) than the previous month, now at 1.2 million -- Microsoft's first summer uptick in years. In terms of usage share, that boosted Bing from 8.4% of US household searches to 8.9%. Google and Yahoo each lost 0.3% usage share, though Google still handles 64.7% of US household searches.

In the expanded search category which takes special services, niche groups, and social sites into account along with general search engines, Google serviced a surprising 4% fewer non-general searches in July than in June. Bing's 5% gain in that period (55 million more searches) cannot account for the amount of Google's drop, down 338 million to 9.2 billion. Part of that drop is due to it just being summer, since other sites' traffic fell proportionately, and social search traffic fell at double-digit rates. But Bing's bucking the trend suggests that the honeymoon hasn't ended yet, and that at least a few million US users are willing to stay out of the pool another minute or so and sample the new player on the block.