Erik Brady, John Kelly and Steve Berkowitz

USA TODAY Sports

Recruiting is the lifeblood of big-time college football and the Southeastern Conference's current run of success may relate to this: During a recent five-year span, SEC public schools spent, on average, roughly $150,000 more per year recruiting football players than did public schools in the other four power conferences.

As a new class of recruits begins formalizing school choices on Wednesday's national signing day, a USA TODAY Sports analysis also finds that in football recruiting budgets, as in many other ways, the gulf between the Football Bowl Subdivision's haves and have-nots is growing substantially. Power conference schools went from spending an average of $247,000 more than non-power conference schools in 2008-09 to spending $360,000 more in 2012-13, the most recent school year for which nationwide data are available.

Overall during that period, spending on football recruiting increased by more than $8.9 million, or about 30%, among FBS public schools — slightly more than the rate at which all operational spending on athletics rose.

USA TODAY Sports analyzed recruiting expense data gathered in conjunction with Indiana University's National Sports Journalism Center from financial reports the schools file annually with the NCAA. The reports ask schools to report income and spending in a variety of categories on a sport-by-sport basis.

No public school spent more on football recruiting than the SEC's Tennessee, with an average of nearly $1.3 million annually — 36% more than any other major college program. Tennessee was the only school over that span to average a seven-figure expenditure for recruiting expenses, which include transportation as well as lodging and meals for both recruits on school visits and coaches on recruiting trips.

Tennessee vice chancellor and athletics director Dave Hart said in a written statement to USA TODAY Sports the difference may be that Tennessee is more diligent in how it categorizes each of its teams' recruiting expenses, and that some other schools may place some of those costs into another category — which, if true, could mean that recruiting expenses at other schools are actually higher than reported.

SEC schools spent an average of $582,000 per year recruiting football players during the five-year period, far more than schools in the other four power conferences — the Big 12 ($450,000), Big Ten ($444,000), Atlantic Coast ($426,000) and Pac-12 ($403,000).

USA TODAY Sports' analysis also ranked schools' recruiting spending based on bang for the buck. Boise State won 55 games from 2010 to 2014 with four finishes in the top 25 of the Amway Coaches Poll for an average of just under $12,000 in recruiting expenses per win. Northern Illinois (57 wins, one top-25 finish) spent even less per win, by $135. Louisiana-Monroe (27 wins, no top 25s) spent the least per win at $7,633. Wisconsin performed well relative to its Big Ten peers with 50 wins, four top-25 finishes and $23,000 in recruiting expenses per win.

"I think we manage our money the best we can and are efficient while serving the needs of the coaches … so we must be doing something right," Wisconsin associate athletics director for external relations Justin Doherty said, adding that "it's not about the money. It's about building relationships with a prospect and a coach."

Tennessee won 28 games over that span with no top-25 finishes for an average of nearly $232,000 in recruiting expenses per win, least bang for the buck. Kansas was next worse with 12 wins and no top-25 finishes for an average of nearly $180,000 in recruiting expenses per win.

"Any expense related to recruiting is included in our NCAA form under that area rather than some costs being absorbed into the regular football or individual sport accounts, which may be the practice of other institutions," Tennessee's Hart said in his statement to USA TODAY Sports. "This practice allows for a higher, and likely more accurate, accounting of true recruiting-related expenses. This includes everything from travel-related costs such as chartered aircraft and commercial flights to general expenses such as those incurred with on-campus recruiting, mailers, office supplies, and etc."

The NCAA's definition of recruiting expenses includes, in addition to the usual travel costs, telephone call charges and postage "and such" plus the value of an institution's own vehicles or planes, as well as the in-kind value of loaned or contributed transportation costs.

"In terms of aircraft, the school plane to which we have access is a UT system plane that is used across multiple campuses," Hart said. "We have limited access to the system plane during peak football recruiting times, which can necessitate more frequent expenditures related to charter aircraft than other institutions with more direct University or athletic department-owned aircraft may experience.

"Additionally, 80% of student-athletes come from outside the state, which increases the recruiting territory we cover and to which we travel in all sports. That said, we do and will continue to invest heavily in recruiting because of how critical success in that area is to the overall athletics program."

The one-year lag used between expense data and win totals is meant to account for the fact that recruited high school seniors do not arrive on campus until the following year. Even so, this remains an inexact measure, as recruiting expenses for any one particular season can stretch back as far seven or eight years. That's because costs can begin when a player is scouted early in his high school career coupled with the reality that redshirt seniors typically spend five years in a program.

Tennessee is not the only place where spending does not equal winning: Of the 25 top spenders on recruiting over the five-year span, 11 have not been ranked in the final coaches poll and five more were ranked just one of those seasons.

Purdue showed one of the largest percentage declines in recruiting expenditures over the five-year span — more than $666,000 in 2008-09 and nearly $480,000 in 2012-13, a drop of 28%. Tom Schott, Purdue's senior associate athletics director for communications, said costs for software shifted from football to a department-wide technical budget during those years, among other cost shifts, lending credence to Tennessee's contention that schools sometimes compute costs differently.

The analysis includes 98 public schools that were members of the Football Bowl Subdivision for the full five years covered. It does not include Penn State because its data for 2008-09 was not available. The analysis for conferences counts the schools that were members of a particular conference in 2012-13 as if they were members of that conference for the entire five years, even if they switched conferences during the span.

Contributing: Nick Penzenstadler, Christopher Schnaars, Matt Slovin of The Tennessean and Matt L. Stephens of The Coloradoan