Donald Trump purchased $4 million of television advertising in four battlegrounds to run over the next 10 days, marking his foray onto the general election airwaves.

The Republican nominee is going on broadcast and cable television in Florida, North Carolina, Ohio and Pennsylvania — states crucial to his prospects and where he is losing to Democratic nominee Hillary Clinton.

Republican media strategists said Trump's $4 million buy was a good start. But it's less than the $5.4 million Clinton is scheduled to spend during the same period.

Clinton has been pounding Trump on television unanswered all summer, and at least for now, will continue to have the airwaves to herself in several other battlegrounds.

Still, Republican insiders said it was encouraging that Trump's first ads were placed in swing states that will decide the election, rather than deep blue states the Republican nominee has claims to have put in play.

That suggests to them that Trump campaign strategists don't believe its candidate's own wild assertions about flipping states like California, Connecticut New York and Oregon.

"She's got a big head start, but something is better than nothing," said a Republican media strategist, who requested anonymity in order to speak candidly. "It's a starting point."

The problem for Trump isn't just that he still stands to be outspent by Clinton over the next 10 days. Clinton is investing more efficiently.

With a robust field and data analytics program, the former secretary of state's campaign is maximizing her advertising dollar to reach specific voting blocs — and for less money.

For instance, the granular level of data tracking on distinct demographics and individual voters allow a campaign to purchase inexpensive advertising time on programs that receive lower ratings overall but are highly watched by particular groups of people.

The Trump campaign didn't build a similarly sophisticated voter turnout operation, choosing instead to outsource most of the work to the Republican National Committee. The RNC does have such a program.

"Having shunned data and any semblance of a media optimization program, Trump's advertising is probably not being spent as wisely as it could," said a Republican strategist who specializes in digital strategy.

Since May 3, the day Trump effectively secured the Republican nomination, either Clinton or her super PAC have been running positive spots touting her record and attack ads targeting her opponent.

Since Clinton launched her general election advertising, Priorities USA, the super PAC supporting the New York Democrat, has piled on with tens of millions more in attack ads. Until Friday, the Trump campaign hadn't run one television advertisement.

Down in the polls to Clinton with time running short, Trump is finally investing some of the money he's raised this summer in an attempt to turn things around. The Republican advertised minimally in the GOP primary and won anyway, and is known to be skeptical of the value of million in television spots.

Trump's first general election buy begins Friday and running through Aug. 29.

Trump is making an initial $1.4 million investment in Florida that includes $441,000 in Orlando; $440,000 in Tampa; $206,000 in West Palm Beach; $157,750 in Jacksonville; $74,500 in Mobile-Pensacola; $40,500 in Pensacola; and $59,750 statewide on cable television.

Clinton is spending $1.8 million in Florida during the same period, and Rick Wilson, a Republican media strategist based there and harsh Trump critic, described his state's portion of Trump's buy as "nowhere near enough to move the numbers."

Clinton led Trump in the RealClearPolitics.com average of Florida polls, 46 percent to 41 percent.

The specifics of Trump's advertising purchase were confirmed with media buying sources and the latest numbers that were available as of Thursday evening.

In addition to Florida, Trump is going up in North Carolina with an 839,000 worth of ads in Charlotte ($347,500;) Raleigh ($220,350;) Greensborough ($108,500;) Ashville ($67,235;) Wilmington ($54,860;) and statewide on cable television ($40,500.)

Clinton is outspending Trump in North Carolina by nearly $80,000 during the same period.

In Ohio, Trump is spending $745,732 through Aug. 29. That includes $224,250 in Cincinnati; $203,725 in Columbus; $116,915 in Toledo; $113,500 in Dayton; $16,800 in Lima and $70,542 on statewide cable.

Clinton is outspending Trump in Ohio by nearly $640,000.

In Pennsylvania, the perennially Democratic state that Trump is most confident about, he bought $984,172 worth of ads in Philadelphia ($518,049,) plus an additional $12,000 on local cable television; Pittsburgh ($211,400;) Harrisburg ($210,900;) and $31,823 on statewide cable.

Clinton is outspending Trump in Pennsylvania by almost $287,000.

"Despite the bluster about Oregon, Connecticut, California and New York, etc. someone in the campaign actually does know where this race will be won and lost: Pennsylvania, Ohio, Florida, North Carolina," a Republican strategist with presidential campaign experience said in an email exchange. "Kudos for getting him there."