I sorta perceive this as a spreading phenomenon. In the early 1990s, I think it started in some cities -- Toronto, Tampa, San Francisco, for examples -- and then as girls and / or patrons and / or the culture spread, it has ended up in a lot of other cities, and some of the newer cities have now taken over the mantle as top-contact cities -- Detroit, Houston (until recently), etc.
I think there are several factors weighing in, but one big one that hasn't been suggested yet is the internet. Basically, resources like TUSCL and (the late lamented) Can-Best strip club reviews, led men to understand the following: "Hey, somewhere else on the continent, there's a chick giving head in a strip club. But at this strip club, even according to a bunch of other guys, the chicks don't give head." From that came the inevitable next conclusion, "I'm going to that other strip club to see if I can get a chick to give me head." And then clubs AND THEIR GIRLS could draw adequate customers only if comparable levels of service were to be offered.
I recall trying to go to strip clubs, and trying to find escorts (like, for full-service; not some damn Ford automobile, doh!), before the internet.
The 80s were tricky. For escorts, in the 1980s you had the yellow pages for the escorts, but that was hit-or-miss and, if you didn't know some rich guys who had already had a few successes with their own swings at the hit-or-miss, then you didn't know what you were going to get into. Or you could take your risks with the street-walker scene, which, in some cities, was vibrant and kinda "normal" (f.e. New York City, Hollywood Blvd. in LA), whereas in several other cities it was just a spinoff of the "pimps 'n' ho's" movement and crack-cocaine addiction in the inner city, therefore dangerous for disease-transmission and for gunfire-risk, and a disgusting experience even if you did find something viable. And for strip-clubs, you had a bunch of cities that were famous for what they had -- Tampa, Vegas, a couple of other tourist destinations -- but those were not necessarily living up to the old vibe. New Orleans, for example, was famous for having a lot of "sin city" but really the 80s were a very clean, drab, and controlloed period for NOLa's strip-clubbing scene. The 1984 World's Fair in the summer had meant that by December 1983 everything "raunchy" had been shut down, and the economic crises of NOLa in the late 1970s (when all the oil industry escaped for offshore tax havens, or for the more friendly jurisdictions of the Texas rather than Louisiana legislature) meant nothing but trashy-trash was going on. Nobody really "knew" what was or wasn't going on anywhere. You couldn't pass safe information, you had no medium for sharing information, etc.. It was much more a seller's market for sex-services; consequently, strip-clubbing was free to remain outside of the sex-services market, for most purposes, with a few variances here or there.
Then in the 1990s, the internet slowly trickled its influence into the whole mix. I lived in Toronto at a time when the internet was really nothing but sex-services and some weird dudes who knew how to run multi-user dungeon programs (which were, in their own right, often just fronts for that other kind of sex-service, masturbation-games over the internet). I recall how slowly the damned pictures would load up on my 26K modem, driving me insanely bat-shit CRAZY as slowly from the top of the picture the girl's hair would appear; then eyes; then nose; and me waiting waiting waiting to see if she was a fattie or a hottie. Canadian internet activity was early, thanks partly to the fact that escorts are more legal (well, uh, "quasi-legal") up there; and thanks partly to the higher percentage of early "wired" families and homes, since the nation was essentially just like the USA except without the USA's lower and upper classes. Strip clubs in Toronto in the 1990s were a boom time for sexual and semi-sexual services, including (but never limited to) the vaunted "lap dance." I think Tampa experienced the same thing. We all had to start defining what the hell a "lap dance" was or wasn't; and less-informed customers and other people are still up in the air about whether or not a certain activity (groping the willie through the clothing without removing or opening any clothing, for example) is to be considered an "extra" for a "required" (and therefore expected) portion of a lapper.
So, I personally remember escort and strip-club web pages popping up as part of the growth of the internet. And I can say from my experience, anecdotally at least, that the rise of these sorts of web pages does also historically parallel, to a good degree, the rise of sexual and semi-sexual services in strip-clubs.