Updated Internet advertising specialist DoubleClick will buy its arch-rival, NetGravity, for $530 million in stock, the company said today. DoubleClick will swap 0.28 of its shares for each NetGravity share, effectively valuing NetGravity's stock at $26.32. The announcement followed the pre-release of DoubleClick's Q2 results, which saw the company post revenue of $44 million, a 154 per cent increase on the same period last year. The company didn't, however, say how much money it actually made -- we'll have to wait for the official results posting for that. For NetGravity, its pre-release revenue was $5.6 million, a 143 per cent increase over the $2.3 million in revenues reported in the same quarter last year. Final figures will be posted on 21 July. ®