It’s hard to fathom who could be excited by the recent revelation that an additional 13 nationally televised Republican presidential debates have been scheduled to take place between now and the end of January. We’ve already endured eight thus far; four are scheduled for this month, then another three in December, and possibly as many as six will take place in January. Indeed, Rick Perry was almost certainly not alone when he complained (but later was forced to backpedal) about the sheer number of the debates this election cycle. But if these mind-numbing affairs rarely shed new light on the candidates and seem to please about no one, why are there so many of them?

Actually, it could be worse. In the old, pre-reform period, when most delegates were selected by state parties and the nomination was decided at the convention, there were only a few debates, usually pegged to the handful of primary elections that existed at the time. But after the nominating process was reformed before the 1972 election and primaries proliferated, becoming the means by which the nomination was formally decided, debates became increasingly common. By 1988, the Democrats appear to have had as many as 42 separate debates by one account, although few of them were nationally telecast. No one much liked this new arrangement except perhaps local groups who sponsored the events, and the practice of frequent candidate forums intended for local audiences died out quickly.

But compared to 1988, there are now three additional factors that have once again increased both the number and the importance of debates within the nomination process. The first is the rise of the cable news networks, which love the inexpensive programming and the chance to showcase their correspondents. (So far this year, the debates have generated excellent ratings for these networks as well.) Recall that CNN dates only to 1980 (just before the convention, after the primaries), and Fox News and MSNBC to 1996, also after the primaries in both cases. Bloomberg TV, for its part, is a bit older, but only recently has become a full-fledged channel. So the demand from the media side of the political arena has certainly increased from the days in which a broadcast network would have to sacrifice both ratings and revenue to host a presidential primary debate.

The second development that’s making for more debates is the changing composition of the Republican presidential field, especially the rise of “business plan” candidates who appear to be running primarily to build a personal brand on which they can later cash in by selling books, hosting talk shows, and giving paid speeches. Both those types of candidates and others such as Ron Paul, who are presumably running in order to raise the profile of minority opinions within the party, have a strong incentive to participate in as many nationally televised debates as possible. It’s true that, in general, candidates who are behind in the polls and have trouble raising money tend to like debates, which give them free publicity and put them on relatively even terms with the frontrunners, but debates also impose costs: When you factor in preparation, they are extremely time-consuming, and therefore inefficient for long shots who need to be spending all their time campaigning in Iowa and New Hampshire to keep their campaigns alive. For candidates without a plausible chance of winning the nomination, however, debates are basically all upside: national publicity, without the messy palm-pumping in Iowa.

But even for money-challenged candidates who do take their campaigns seriously, recent changes in fundraising technology have made nationally televised debates a decidedly more effective lever. Until recently, fundraising was almost completely candidate-driven, depending in large part on candidates and their staffs reaching out to highly-prized lists of donors. Of course, that’s been upended by technology; nowadays, any positive publicity for a candidate has the potential to generate plenty of fundraising online without the campaign doing anything at all beyond processing the transactions. Candidates, especially those unlikely to win the nomination for whatever reason, are therefore increasingly opting for the national stage of televised debates over spending time camped out in Iowa living rooms and New Hampshire diners. And the cable news networks are happy to accommodate them.