American surfers viewed more than 12 billion web videos during May, new research reveals.

The latest Video Metrix from comScore said that the figures represent a year-on-year increase of 45 per cent.

Google Sites once again ranked as the top US video property during the month with 4.2 billion videos viewed (35 per cent share of all videos viewed). YouTube accounted for more than 98 per cent of all videos viewed at Google Sites.

Fox Interactive Media ranked second with 778 million videos (6.4 per cent), gaining 1.3 share points on April.

Yahoo Sites ranked third with 347 million (2.9 per cent), followed by Microsoft Sites with 246 million (2 per cent).

The research also noted that almost three-quarters of the total US internet audience viewed online video. The average online video viewer watched 228 minutes of video.