Product review (5 stars): Filters Are Now Cost Effective And They DO Last 3 To 4 Months If You Maintain Them Properly!  Lesson Learned!!
Update (11-24-2015)  I have returned to upgrade my earlier review of these filters after having used my Wemo Humidifier for over a year now. Here's what I've discovered.  If you keep the filters moist they will indeed last 3 to 4 months.  And Holmes is now offering the filters here on Amazon for six or seven dollars less than they had been priced ($24.99 or 95 I forget which now down to $17.99 as of this writing) and with 4 months service that is a reasonable price for a set of whole house filters.  I also recommend bacteriotstat to keep contamination out of the water itself and you're good to go.

I love the programmable aspect of the humidifier and the Wemo app works great on my smart phone and on my tablet.  It keeps me informed of water levels and the 7 day timer works great.  So I am here to eat crow and recommend these filters now.  Hope this helps you decide.

Original Review:

Two filters you need for the new Wemo WiFi humidifier, about every sixty days.  Way...Way...Way...Overpriced.  Figure on around $150.00 a year.

Nice game.  The humidifier itself is amazing but of course you're tied to these expensive cheaply made paper/plastic filters for life.

Update:  03-04-2015  Have now experienced the drying out problem others have written about and it's true.  Once the filters are dry they never give 100% output again.  About 70 to 75% output after the first drying and exponentially decreasing thereafter.  I soaked them for thirty minutes as Holmes suggests and they were literally falling apart.  The black plastic grid was just breaking into little pieces.  What a mess!

I whole heartedly agree that a machine that works as effortlessly as this should have filters that work and function just as effortlessly.  That would be worth the $24.95 or whatever replacement cost, but since the drying problem is inevitable unless your obsessive compulsive they are not worth the outlay...and that means that this wonderful piece of technology becomes frustrating to use and useless in the long run.

My recommendation is not to buy until Holmes has addressed the filter issue and offers much better filters at reasonable prices.  I am putting my old humidifier back in because it works and the filters last and don't cost an arm and a leg. (this i didn't wind up doing because I had two filter sets to use up in the Wemo Humidifier and during the process of using them and because the unit would warn me when water was low I discovered that the trick is not to let them dry out).