In West Virginia mine country, television ads say President Bush (search) has "broken his promise to invest in coal." In Wisconsin, voters see spots saying the factory state "has lost 84,000 manufacturing jobs" under the Republican. And Florida's large retiree population gets a commercial that claims Bush's policies have "banned Americans from buying low-cost drugs from Canada."

Voters in most of the states considered battlegrounds (search) in this year's presidential race are seeing ads made just for them, focusing on their particular issues, as both sides work to influence the outcome on Nov. 2.

In the past, campaigns used a one-size-fits-all approach to advertising with standard spots on big-picture issues such as jobs, education and health care.

But over the past few election cycles, they increasingly have keyed in on local issues in hopes of grabbing the attention of certain groups of voters who are flooded with information from multiple sources.

Advances in technology have made it easier for campaigns to make several versions of the same ad or to cut one commercial for one media market. Using computers, ad makers can turn around a spot overnight, since it takes only minutes to electronically remove the name of one state and insert the name of another.

Last month in Nevada, Bush and Massachusetts Sen. John Kerry (search) engaged in an on-air spat over a divisive statewide project: the national nuclear waste dump planned for Yucca Mountain outside Las Vegas.

Democrats have criticized Bush for approving the repository, saying he broke a campaign promise from four years ago to base such a decision on sound science. Republicans say Bush kept his word.

Sensing that the criticism could sway voters in the important state, Bush launched a TV ad claiming Kerry has voted "to make it easier to dump waste at Yucca" and "tried to speed shipment of nuclear waste from Massachusetts to Yucca."

Kerry's campaign lashed back with a commercial saying Bush "went back on his word" after "promising to keep a nuclear waste dump out of Nevada."

Over the past two weeks, Kerry's campaign has run ads in cities where the president was campaigning. While Bush was in Parkersburg, W.Va., one ad said he promised "$2 billion for clean coal technology." It goes on to say that "four years later, Bush has broken his promise to invest in coal, and cut $15 million from mine safety."

In Milwaukee, another Kerry ad said Bush promised "to keep our economy growing" and "expand opportunity." "Four years later," the ad says, "Wisconsin has lost 84,000 manufacturing jobs."

For his part, Bush's campaign began running tailored ads in April with nine spots accusing Kerry of voting against a specific type of military fighting vehicle produced in certain states.

An ad for Maine alleged "Kerry wanted to cancel Aegis Warships built here in Maine at Bath Iron Works." A similar version focused on the Apache helicopter and the Tomahawk cruise missile "built here in Arizona." A third said: "John Kerry has repeatedly opposed weapons vital to winning the war on terror: Bradley Fighting Vehicles, F-16 fighter jets and Aegis warships, components of which are all built here in Ohio."

The implied message: voting against the systems translates into fewer jobs at the plants that make them.

Outside groups, mostly on the Democratic side, have used the technique, too.

The League of Conservation voters has hammered Bush on offshore drilling in Florida, while the Media Fund has peppered the airwaves in Ohio, a state struggling to recover from the recession, with job-loss spots.

The Democratic National Committee, meanwhile, recently rolled out a new prescription drug ad for Florida and its large elderly population. It claims that Kerry will "stand up to the drug companies" while Bush has "blocked Medicare from negotiating lower prices and banned Americans from buying low cost drugs from Canada."