The online fashion retailer Boohoo.com posted strong revenue growth during the three months ended 31 May 2015 thanks to a good performance in its UK and international markets.The group's total revenues were up 35% or 45% on a constant currency basis to £41.3m and the number of active customers rose 32% to 3.3m.Its spring/summer #WeareUS campaign drove its UK sales up 27% to £26.3m.Despite currency headwinds, sales in the rest of Europe rose 27% or 45% on a constant currency basis to £4.9m.The rest of the world was the strongest performer, with sales up 66% or 70% on a constant currency basis to £10.1m, thanks to investment in price and marketing initiatives.Furthermore, its investment in the warehouse is on track and the company plans to start using it from July.Joint chief executives Mahmud Kamani and Carol Kane said: "Whilst we have invested in accelerating our growth during the quarter, our important peak trading periods are yet to come."The board's expectations for full year profit remain unchanged."N+1 Singer analysts said the trading update was the "first key milestone for investors, providing significant reassurance and confirmation that the growth strategy is back on track".The broker added that forecast assumptions look deliverable, and may lead for some additional customer recruitment.Following the trading update, Boohoo gained 3.75% to 26.98p on Tuesday at 09:29.