Paid forum posting

In and of itself, it's a suboptimal means of making money, as there's loads of better things to do that pay more. It pays poorly per work done (about $.07 per 50-100 word forum post, based on current averages on sites like Postloop), meaning you'd have to work 1-2 hours to earn $5. You could earn more in a freelance arrangement or on a gig site (Fiverr has several sellers doing 15-25 for $5, or $.20-$.33 per post), but the market price stays in that low zone.

On the bright side, paid forum posting is much easier to do than article writing if you have decent English, and can help partially subsidize your link building efforts. I.e., join Postloop, pick the forums that relate to your niche site and will let you post a link, and just write posts for those sites, thus boosting traffic and sales for your own promotions.

Or, you can double up on the forum post payments---create a gig stipulating you will do 15-20 posts with links to forums of your choosing, then post to your Postloop selected forums. Get paid by the gig buyer, and by Postloop, for the same forum posts!

You have to be a good writer for that,with a 49% talent and %51 work

I'd say at first, it will feel like a waste of time, because you will earn very little! However, if you like it and if you manage to increase your rates, you could be earning a nice revenue. You won't get rich though..

I used to sell forum posting services on Fiverr and charged $5 for 20 posts. I made around 150 sales with it with a lot of them being returning customers. Rates vary depending on what site you sell your service on. There is additional side money to be made from it, although it shouldn't be your main income source.