There are very valid points made on this thread.
Yes, posting off-topic content clearly for marketing purposes, may be out of place on a very niche blog.
However, it does not necessarily seem out of place on a more generalist blog.
The main thing is to make sure that you have good navigation on your blog site. You can do this by adding categories, or separate pages.
You could always link to your other site on your blog. Doing so would not be out of place on an About page, or in a widget, for example.
Keeping to a posting schedule is indeed important, although I personally don't think it need be every day.

The main thing is that, whatever content you post on your blog, should add some sort of value for the reader.
For instance, I once saw a blog from a small insurance broker with about 50 very thinly-veiled advertisements for various types of insurance. Some that I had never even heard of and I used to work for an insurance company as an accountant.
I ask myself, why on earth would anyone sit and go and read through any of that content? So I can find out why university students should take out life insurance just in case they die (of alcohol poisoning, I am assuming) to give their parents financial piece of mind. Another topic was about flash floods.
This sort of advertising preys on the fears and phobias of humanity. (Although, you should identify risks and manage them pro-actively.)

However, I can't imagine being in any way offended reading a travel blog, where someone is using a camper to travel all across the country, taking photos of the various places they go to - with a few smiling faces standing in front of a camper, waving to the camera.
Which brings me to my point that you don't necessarily have to do all your blogging yourself.
You could always get someone who has a travel blog (and even an established following) to market on your behalf.

And yes, Google does penalize paid links. But somehow I doubt one (or five) travel bloggers receiving some sort of gratuity for their advertising is going to be viewed on the same level as buying a thousand likes on Facebook.