NEW YORK (Dow Jones)--Retailers are expected to post a record $1.2 billion in online sales this Cyber Monday, only the second time a billion dollars in online commerce has occurred in one day. The estimate, by online tracker comScore, compares with last year's $1.03 billion and shows the power that Cyber Monday carries with holiday shoppers. Cyber Monday "is increasing in importance, with virtually all retailers getting involved and more consumers knowing about it as a day for big discounts," said comScore analyst Andrew Lipsman. "And we are seeing some strength in retail spending as savings rates have gone up, giving consumers more confidence about spending during their holiday season." By Coremetrics's estimate, online sales on Monday were up 15% through 2:25 p.m. EST from a year...