Molko's band supported Bowie in 1996, featured at his 50th birthday celebration the following year and released a duet of 'Without You I'm Nothing' in 1999.
"It's a great record and it gives me a lot of hope," Molko told Digital Spy of Bowie's shock return with The Next Day.
"I probably wouldn't have written a song like 'Too Many Friends' if I actually was on Facebook and if I actually did tweet.
"I'm not too sure that it's actually bringing us all together. I'm not too sure that it's not actually creating a new form of social alienation.
"People don't call each other on the phone anymore and have real conversations. As a consequence, I'm a very private person. I don't social network."
Molko added: "If Bowie can make a record in complete anonymity without anybody knowing about it and without it being leaked and without it coming out and surprise everybody the way that he did - and to come back with such a wistful track like 'Where Are We Now?' - then I think there's hope for us, there really, really is. And hats off to him. Touché. Well done David."
Asked if the time spent away was part of the reason for the overwhelming positive response to the album, Placebo guitarist Stefan Olsdal said: "The tracks I've heard I really like. If it's because he went away, I don't know. I suppose people like a bit of a comeback story."
Drummer Steve Forrest added: "Maybe they'll take notice of it more because of that, but then the record still has to speak for itself.
"If it was s**t, people would be like, 'Oh David Bowie's back! But he's back with a terrible record. What's he doing?!'
"But he didn't. It's David Bowie, of course it's going to be a good record. The man still knows how to write a song."
Of calling the new Placebo album Loud Like Love, Molko admitted to having some "mischievous glee" about putting "love" at the centre of the album.
"Nick Cave wouldn't have made a record called 'Do You Love Me?' when he was in The Birthday Party," he said.
"It's a fantastic record. It's pure Nick Cave and it's dark as f**k. It's true, though. When you say the word 'Love' it directly conjures up something light and bright.
"But it's true that the title track is quite upbeat and celebratory, but things get very dark... they get darker and darker as the album progresses."
He added: "After all, this is Placebo. We were never going to make a record that was ten love songs.
"Being Placebo, we were always going to explore themes of obsession and jealousy and heartbreak and absence of love and how addiction can tear people apart.
"One of my favourite songs ever is 'Love Will Tear Us Apart' by Joy Division. That's not the happiest song either!"
Of three songs ('Too Many Friends', 'Scene of the Crime' and 'Hold on To Me') starting life as Molko-only solo demo recordings, Olsdal said: "I think it makes the album a bit more varied and a bit more eclectic for sure.
"The way Brian writes lyrics, they're open enough to make your own stories within them. It's never a blatant page out of a diary."
Asked about their move away from a major label and return - to Universal - with the new record, Molko said: "We did that as a reaction to our contract with Virgin/EMI coming to an end - coming to something of a sour end, I must admit.
"By the time that we made our last record for Virgin/EMI, the people that had signed us and discovered us, and worked with and we'd built the story with Placebo had all been fired."
He added: "Our record company that we'd been releasing records under, Hut Recordings had closed down and the record company had been taken over by a private equity firm. Everything became about the bottom line.
"We felt like they didn't really know what to do with us at all by this point. There was nobody left that we had a relationship with, a really good, creative working relationship."
Molko said: "We decided to go to the other end of the spectrum - fund the recording of the album ourselves, which we did before funding a deal with PIAS.
"That was an interesting experience. It taught us how much f**king work it is doing, and to a good degree work we're not best suited to doing."
Olsdal said of the current Placebo lineup: "We're in an incarnation where we actually enjoy each other's company and can work in a studio without this big black cloud hanging over us that there was for a certain period. We appreciate what we have a lot more."
Of the effect of reality TV talent contests on the music industry, Olsdal said: "It's just feeding the culture of fame and celebrity.
"It's a vacuous, fast-track route to an idea... and with that kind of fast-track you don't have to prepare yourself mentally and it takes your whole system by surprise and it's a shock.
"It's so hard to sustain. It's not a natural way to go about it and ultimately it doesn't lead to a satisfying, long career. It just feels like it's fodder for a TV mogul's project."
Forrest added: "It breaks a lot of hearts. The people who get into it [do so] because they think that's how you make it as an artist, and that ain't [the case]."
Placebo's seventh studio album Loud Like Love is out now.