Bloomberg reports Twitter (TWTR), which stated in its public S-1 it's looking to raise $1B, is now looking to raise more than that. The news service adds Twitter will be paying underwriting fees of 3.25%, well above the 1.1% charged to Facebook but below the 5.7% averaged this year by U.S. IPOs.
One issue likely to come up during Twitter's IPO roadshow: the fact U.S. user growth is stalling. App developer Onavo estimates the percentage of iPhone owners using Twitter actually fell fractionally between March and August, to 27%. By contrast, Instagram's share rose to 38.3% from 34%, and Snapchat's to 20.8% from 13.2%
Give Twitter's Q2 U.S. ad revenue per 1K timeline views was over 7x international levels, a lack of U.S. user growth stands to have big top-line implications.
Onavo's numbers follow an AllThingsD report indicating Twitter is dealing with heavy churn, as new users accustomed to Facebook's more conversation-centric UI become intimidated by Twitter's "firehose" of 140-characters-or-less updates.