... are membership sites still profitable as it used to be ...
OMFG YES, and let me tell you what I find works AMAZINGLY well...
I started a site about a year ago and all I use it for is to setup little "mini membership" sites. Each sites offers tidbits about their respective niches. I post 4 - 5 articles each month and send a notice via mailing list to all members.
Now, I only charge $4 - $7 per month
BUT with many members for each "mini" site, the $$$ adds up quite nicely.
The key is to remain actively involved, and on point, as much as possible. No one wants steal or irrelevant information. All keeps things updated and continuously provide fresh valuable content.
Setting up a "mini" membership site like this is extremely simple to do too and can even be done on topics you know NOTHING about.
For example, if you've ever met me in person, you would know I am THE LAST person who you would ever expect to receive health and fitness tips from. I am overweight (partially due to a disability, but mainly due to my love of food, LOL), I smoke almost a pack and a half a day, ALL I drink is soda (or "pop") AND I LOVE LOVE LOVE my deep fried foods...
Now, even still, a few of my very very successful minisites focus on the H&F industry.
As I said above, I know nothing about it (but learning more and more each month), but going out and doing a little bit of research isn't that difficult. Plus, each "research session" I find enough info for 5 or 6 months worth of content. Drop-feed those into a blog or an autoresponder series and you're all set...
Now, obviously there is a little more to it than just what I posted above, but I am sure you get the gist.
Anyway, the answer to your question? YES and they're relatively easy to setup and maintain (if don't right)...